Fits Bioluz 2700K 4" 15W LED Diffusion 90 degree (listed). I have placed a 4" Torchstar 15W 2700K next to this one for direct comparison. Torchstar is listed as a 130 degree diffuser. I placed them side by side about 3 feet apart on a wall. I can say without a doubt these bulbs are identical. Same color, same brightness, same dimmer, same dispersion pattern, same clips, same Edison adapter, same plug, everything. So this rating goes for both. Why 5 stars? Because these things are bright! Youโฆ