WEEGrow

This bulb is well-built and super bright. It's about 5 inches in diameter mainly because the cooling fins extend the surface area and dissipate heat, which also makes it very heavy. The positive side is it'll keep cool even if left on for an extended period of time.

I got this for my terrariums that need light but sun from my window is too much and burns them. I can adjust the 4 heads to get all of them and so far they are doing much better. Will likely be buying another.