UltraFire WF502B Flashlight CREE XM-L T6 LED 3 Output Run on 18650 3.7v Battery NOT Included CREE XML T6 with 900+ Lumen output with Integrated Belt Clip 3 Mode Output: High - Low - SOS- Aluminumalloy casing with o-rings for water resistant design.as compared to 501B it has a belt clip Can be mounted on tactical rail with 1" ring mount Rugged, anodized, CREE LED designed to last 100,000 hours