With all optics, the higher the number, the wider the spread of light. However, the more you spread the light, the less it penetrates deeper tanks, and the lower the PAR values will be. It is best to find a happy medium between spread and penetration. As a rough guideline, use the following to estimate spread on all Coral Compulsion bulbs:
120 Degree : Approx. 21" x 21"
90 Degree : Approx. 18" x 18"
60 Degree : Approx. 12" x 12"
These optics are compatible with all Coral Compulsion PAR38 or PAR30 bulbs.
Changing out the optics is as easy as removing the screws on the faceplate of the bulb, and replacing each lens.
If you want the optics swapped out on a new bulb, let us know ahead of time and add the additional optics to your order and we can change them for you, free of charge.