SSC P7 LED Replacement Module 900 Lumens Drop-in for Ultrafire 501b or 502b SSC P7 900 Lumen Drop-in Replacement LED module that Fits Ultrafire 501b or 502b 900 lumens of wide dispersed light Will also fit maglite and other flashlights that can accommodate LED module that is 27mm in diameter 30mm deep Dimensions: 27mm diameter at the widest part & length 30mm (springs not included), 47mm (w/springs) Have a backup or upgrade your existing flashlight