Part # NA704

Dimensions 6-3/4" L x 5" W x 5" D

Alternate Part #'s 79102200, SPP-1421, SPX503Z5, 57-555-1035, APC120400M, ELER40FL400-HG, R400FL400/HG, SPG-301-7683

Product Description


Specially designed to keep your pool well lit this season. Our bulbs are made with thicker filaments and glass to last longer. Heavy duty heat shielding prevents damaging heat build-up and prolongs the bulb's life.

* Dimensions may vary slightly


Remember when replacing your pool or spa light bulb it is very important to replace the lights lens gasket. After long use, heat, and harsh chemicals, the old gasket is probably compressed, and if it doesn't fail immediately, it might fail before the next bulb change. Click here for Pool Light Lens Gaskets

For additional pool & spa light bulbs

Product Specifications

400 W
120 V
R-40 Medium
Dimension A:
6-3/4 in.
Dimension B:
5 in.

?     Asked on 12/29/2011by Guest

Will this light bulb work on a Hayward Astrolite?

A  Answered on 12/29/2011 by InyoPools Product Specialist Patrick P.

Yes, this bulb does work on Hayward Astrolite, as well as other makes and models of pool lights. The most popular of these lights being Pentair Amerlite, Hayward Starlite, Haward Duralite, and Sta-Rite SwimQuip Lights. Click here for a full listing of our >Pool Light Bulbs & Spa Light Bulbs.

?     Asked on 6/29/2016by steve

I have an American products underwater light(wet niche type) model is R-400 BCL. the gasket I see on your site is 791016. the bulb is an R 40 reflector bulb p/n 993650, not sure which bulb that is you have listed. other #'s on the light are 98708400 & L 777985. thank you for your help.

A  Answered on 6/30/2016 by InyoPools Product Specialist Megan C.

Hello, Steve. The part number for  R-400 BCL cross-references to the Pentair Amerlite Pool Light and the part number 98708400 cross-references to the American Products - SpaBrite & Aqualight. I best recommend verifying the voltage and watts on your current bulb or the casing of the fixture. You may find this link helpful as well. Click here to view How To Identify a Replacement Pool Bulb / Light.

?     Asked on 11/5/2016by fred

I need to replace a light bulb in a 15 year old pool light. No label left on the light fixture. American Products Co is embossed on the approx. 8" diameter glass lens. The niche is part # 792067 (Pentair?). Circuit is 120V. Must the new bulb be exactly the same watts as the old one or could I just use a 400W bulb? I assume the gasket is the 8 1/2 inch version such as LPL-G-P or 3525-07? I love the details you give on your website! Thanks!

A  Answered on 11/7/2016 by InyoPools Product Specialist Stacey M.

Hello Fred, from what the niche light it connects too there is only American Products - SpaBrite & Aqualight Parts that you can use which depending on volts/watts would work in your light.

?     Asked on 5/16/2019by joyce

I need a new pool light. I removed the blub. On the inside the label reads 400 watts 120 volts R-40 bulb type. It also reads model 7884XX, 7844XX, 7894XX... could you please tell me which blub and casket I need

A  Answered on 5/18/2019 by InyoPools Product Specialist Lennox H.

Hi, Joyce. This is the correct replacement bulb. You will also need the Lens Gasket - 79101600 (OEM) or 791016 (Generic). 

?     Asked on 3/15/2020by Garett Seeba

Is this bulb the correct one for this housing. I don’t see you have a 300w version?


A  Answered on 3/16/2020 by InyoPools Product Specialist Lennox H.

Hi, Garett. It is NOT, the correct bulb is P/N Q300T3C/120 along with the Amerlite Lens Gasket - O-170

  • Commented on 3/16/2020 by Product Owner

    That shows a non screw type bulb my fixture takes a bulb that screws in..


    • Commented on 3/16/2020 by InyoPools Product Specialist Lennox H.

      Garett, The fixture label has T3 R7S as the bulb type, this 400W, 120V, R40 bulb can be used with your fixture.


Est. Repair Time

Less than 1 hr

Tools Needed


Pool Light need replacement

Written on 6/29/2020 by Guest

To replace light bulb in pool light: I shut off the power at the circuit breaker. Removed the one screw holding the light in place and attached to the side of pool. I then proceeded to take the light completely out of the pool.

Removed all the screws holding the light cover in place. Removed the old light bulb and placed new bulb. Be sure to change the gasket for your pool light to insure a tight seal ( this product also sold by Inyopools.com). Tighten all of the screws firmly and placed light back in pool. Turn on circuit breaker.

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