Mega-Ray 275W Mercury Vapor UVB BulbProfessional & Zoo Use, Tall Enclosures (36–42in Basking Distance)
$51.95
275-watt Mega-Ray mercury vapor UVB + heat bulb for zoo, rescue and veterinary enclosures with a 36–42″ basking distance — not for standard home fixtures.
🏆 Proven 10-Year Track Record– The original Mega-Ray design
📉 Slow UVB decay – independently measured at just 15% loss after a year (UV Guide UK)
☀️ Natural Sunlight Simulation – Prevents metabolic bone disease
✍ Self-Ballasted Design – No external ballast needed
🛡️ Magnesium Oxide Inner Coating – Mega-Ray’s translucent coating design
🇩🇪 Made in Germany – Free US shipping, 30-day returns on unopened bulbs, 6-month warranty
Satisfaction Guaranteed
- Free US Shipping
- Authentic Mega-Ray
- 6-Month Warranty
- 30-Day Returns (Unopened)
Why it costs $51.95
- The price is set by Mega-Ray, not by us. It is the same at every authorised seller, so there is no cheaper genuine bulb to find by shopping around. If you see one well below this, it is worth asking where it came from.
- Shipping is inside that number. US shipping is free and there is no handling fee. The price on this page is the price at checkout.
- Made in Germany, shipped from Mega-Ray’s US distributor. We are a small Tennessee store, not the manufacturer, and we do not pretend otherwise.
- We hold no inventory. Your bulb ships from the distributor’s current stock rather than off a shelf here, which is the only claim about freshness we can actually stand behind.
Compare all four Mega-Ray bulbs
Every Mega-Ray puts out the same UVB at its working distance. What differs is how far above the animal it has to sit. Measure from the bulb face to your reptile’s back, then pick the bulb whose range covers it. Not sure? Start with the wattage guide.
| 70W | 100W | 160W | 275WMost orderedYou are viewing this one | |
|---|---|---|---|---|
| Who it is for | Leopard and crested geckos, corn snakes, anoles, juvenile red-footed tortoises | Bearded dragons in 40-gallon enclosures, red-footed tortoises, basking turtles | Adult bearded dragons in 4×2×2 enclosures, monitors, iguanas, red-eared sliders | Zoos, breeders and tall enclosures. Not a consumer bulb |
| Working distance | 6–12″ | 12–20″ | 18–24″ | 30–48″ |
| Optimum distance | 8–10″ | 14–16″ | 20–22″ | 36–42″ |
| Closer than this is too close | 6″ | 12″ | 18″ | 30″ |
| Fixture required | Ceramic socket rated above 70 W | Ceramic socket rated above 100 W | Rated above 160 W. Most reptile clamp lamps stop at 150 W | Porcelain keyless lampholder rated above 275 W |
| Price | $48.95 | $48.95 | $48.95 | $51.95 |
Free US shipping on all four. Prices are set by the manufacturer, so nobody sells a genuine Mega-Ray for less.
Common questions about the 275W
Will the 275W fit my fixture?
It needs a ceramic socket. Porcelain keyless lampholder rated above 275 W. Mega-Ray asks for a fixture rated above the bulb’s own wattage, and this is the single most common mistake we see — a standard reptile clamp lamp is usually rated to 150 W, which is not enough for the 160W or the 275W.
How far above the basking spot should it go?
Measure from the bulb face to your reptile’s back, not to the floor. The 275W works between 30–48″, and 36–42″ is the sweet spot. A screen lid takes out roughly 20–40% of the UVB, so mount closer to the near end of the range if the bulb sits above screen.
Can you still buy mercury vapor bulbs?
Yes. The US Energy Policy Act of 2005 prohibited the manufacture and import of mercury vapor lamp ballasts after January 1, 2008, not the lamps themselves. Mega-Ray bulbs are self-ballasted, so they have no separate ballast and were never covered. More on how self-ballasted bulbs work.
How long does it last?
Plan on replacing it every 12 months. UV Guide UK measured a self-ballasted Mega-Ray at about 15% UVB loss after a year and 17% after 18 months, which is slow for this lamp type, but output does fall steadily and a bulb can fail without warning. See the independent measurements.
What are the downsides of a mercury vapor bulb?
It produces heat and UVB together from one socket, so you cannot adjust them separately — and you cannot run it on a dimmer or a pulse-proportional thermostat, which will destroy it. It also needs the mounting distance above to be right, because you cannot turn the UVB down. In a tall or wide enclosure that single-point output is an advantage; in a very small one it is not.
Is it safe to use over my reptile?
At the distances above, yes. The 2014 independent test found no UVC at all and confirmed the glass blocks wavelengths below 295 nm. The risk with any mercury vapor bulb is mounting it too close, which is why the minimum distance on this page is a hard floor rather than a suggestion.
Still not sure? Email us and we answer within one business day.
Description
Description
✅ This is the right bulb if you run a zoo, rescue, clinic or other facility with tall or walk-in enclosures where the bulb face sits 36–42″ above the animal. For a home enclosure the 100W or 160W is the correct bulb. PO numbers accepted at checkout; quotes and W-9s by email. Free US shipping, 30-day returns on unopened bulbs, 6-month warranty.
⚠ Check your fixture rating. Standard reptile clamp lamps are rated to only 150 watts and must not be used with this bulb. You need a porcelain fixture rated above 275 watts: a porcelain medium-base keyless lampholder rated 660 W (Leviton 9875 or equivalent), hard-mounted in a metal reflector or hung on its own cord above the enclosure. Brooder clamp lights are rated only 200 W for PAR38 bulbs and do not qualify. Using an under-rated fixture is a fire risk. See the fixture rating guide →
This is a professional / zoo bulb. Its optimum basking distance is 36–42″, so it is not suited to most home enclosures. Check which Mega-Ray bulb your reptile actually needs →
Ordering for a zoo, clinic, or rescue? See our facilities page → — PO numbers at checkout, quotes and W-9s by email, and quantity orders shipped fresh from the distributor’s stock.
Keeping a tortoise? Read the tortoise UVB and heat guide → — barns, greenhouses and tall indoor pens, with the 275W 36–42″ above the shell and never under 30″.
Is the 275W the right bulb for you? (Almost certainly not, unless you run a facility)
Mega-Ray’s own guidance on this bulb is unambiguous: “THIS BULB IS A ZOOLOGIST BULB. NOT INTENDED FOR PERSONAL USE unless you need UVB within the optimum distance of the bulb for your habitat.”
Its optimum is 36–42″ from the animal’s back — a distance that exists in zoo enclosures, rescue rooms and walk-in habitats, and almost nowhere in a home. Mounted at a typical home height it delivers a serious overdose. There is no consumer species category that maps to it.
| Bulb face to the animal’s back | Verdict |
|---|---|
| Under 30″ | Do not use this bulb. Overdose range — the 100W or 160W is the correct bulb for that height |
| 30–48″ | The 275W’s working range |
| 36–42″ | Optimum |
| Over 48″ | Below useful UVB |
Who buys it: zoos, rescues, sanctuaries, universities and veterinary practices with tall or walk-in enclosures. We sell to facilities at the same listed price, take a PO in the order notes, and can send a quote or a W-9 by email — see the facilities page.
Fixture: a ceramic socket rated above 275 watts. No standard reptile clamp lamp qualifies; use a porcelain medium-base keyless lampholder rated 660 W (Leviton 9875 or equivalent) in a metal reflector, hard-mounted or hung on its own cord. Brooder clamp lights are rated 200 W for PAR38 bulbs and do not qualify.
Screen tops: at these distances the lamp is almost always mounted above an open enclosure. If a mesh panel is in the path, subtract 20–40%.
New to mercury vapor bulbs? Read how they work, which wattage and how far away → — the self-ballasted design, the full distance table for all four bulbs, fixture rules and what independent testing measured.
📉 Independently tested
UV Guide UK measured a self-ballasted Mega-Ray at −15% UVB after one year and −17% after 18 months of daily use, where other mercury vapor lamps in the same test series lost 60–70% in their first 100 hours. The glass blocks everything below 295 nm — no UVC — and the inner coating throws a wider beam than a standard PAR38. (F. Baines, UV Guide UK, 2006 and 2014.) We still recommend replacing every 6–12 months, or when your Solarmeter says so.
In the BIAZA UV-Tool (Baines et al., Journal of Zoo and Aquarium Research, 2016 — a peer-reviewed assessment of 24 reptile lamps co-authored by Chester Zoo, Marwell, ZSL, Durrell and Bristol Zoo), the Mega-Ray 100W and 160W are rated as able to provide a suitable UV Index for all four Ferguson zones, one of only five lamps in the table to do so. Read the paper. See every measurement, the methods and their limits, on our test-results page.
🔬 Technical Specifications
| Wattage | 275 Watts |
|---|---|
| Bulb Type | Self-Ballasted PAR-38 Narrow Flood |
| Working Distance | 30–48″ from the bulb face to the animal’s back (optimum 36–42″) — see the distance table above |
| Minimum Distance | 30″ from the animal’s back — never closer |
| Recommended Replacement | Every 6-12 months |
| Suitable For | ⚠️ THIS BULB IS A ZOOLOGIST BULB. NOT INTENDED FOR PERSONAL USE UNLESS YOU NEED UVB WITHIN THE OPTIMUM DISTANCE OF THE BULB FOR YOUR HABITAT |
| Voltage | 120V (North America) |
Important Safety Information
- Must use wire dome fixture only – Plastic fixtures can melt
- Never closer than 30″ to the animal’s back — optimum 36–42″ (see the distance table above)
- Allow 15 minutes cool-down before moving if accidentally bumped
- Use with Solarmeter 6.5 for optimal UVB monitoring (recommended)
Reviews
There are no reviews yet.