OP Cree XM-L U2 1A 1000 Lumen 3.7V~4.2V 5-Mode LED lamp（xml drop-in）
Led Brand: Cree XM-L U2
Brightness: Max 1000 lumens
Ok bought 10 of these for drop in on 501 .They put out 550 lms Measure the amps off the tail cap find lumen rating from Cree who I use to work for and that's the output. High 550 lms, 285 lms med , 80-60 lms low. You do not need any higher than that . I have multiple flashlights and work with them everyday anything else is waste of money and battery power most time I run on med.