I have a Glock17 with TSD Tactical slide milled for the RMR. It lasted about 750 rounds and the light started intermittently working. It eventually went out completely right after that. Everything was snug and pictured so movement was not an issue. If anything it looked like the battery moved slightly during cycles. Well Trigicon repaired it and has been very quick to help great customer service!! Well upon return and replacement of electronics as noted on repair order I remounted it and took it out to Zero In and it lasted about 30 rounds and completely went out again. I was very disappointed and talked to the Trijicon rep. Who is going to have another look at it. I hope this was a bad batch but apparently they don't have a recall or service batch notice at this time. I love my Trigicons and so far their Customer Service is top notch as well.