Sunbox will be closed from May 2 to May 14.

Please email and we will respond as quickly as possible. Please include your phone number if you would like a return call on the days we are not in the office. Thank you for your understanding, stay well and have a sunny day!


FBO31/850K Replacement bulbs for SunRay, SunRay II and SunSquare FREE SHIPPING (lower 48 states only)!

SKU: SB-594 Category:


Special Internet Price
Replacement bulbs are non-returnable and non-refundable.

This is the replacement bulb for all SunRay, SunRay II, and SunSquare light boxes. Sold in packs of 4 or 6.


SunBox now offers new energy-efficient 10,000 lux bright light bulbs. Low mercury technology means less mercury and a environmentally safer bulb.

These new 850 bulbs provide a brighter white and higher color rendering over the 750 bulbs. This new technology makes this the perfect time to replace your old bulbs!

SunRays take 4 bulbs and SunSquares take 6 bulbs.

Download your Replacement Bulb Instructions:


  • Easy to Install 
  • Replacement Bulbs: All bulbs for 110v-220v and world voltage units
  • Fits: SunRay, SunRay II, SunSquare+ models
  • Watts: 31 – 5000K
  • Dimensions: 23″ Length
  • Instructions: Order the 4-pack to replace all bulbs in your SunRay or SunRay II. Order the 6-pack to replace all bulbs in your SunSquare+.

Please open and inspect your package within 7 days of receipt.

Replacement bulbs are non-returnable and non-refundable

97 Monocacy Blvd, Suite C, Frederick, MD 21701 240-651-3286 1-800-548-3968