Laser pointer holder for picatinny rail. all you have to do is pull the laser in a few mm and it will engage and depress the switch. Laser fits snug while in off position, but even better when on....Thingiverse will not allow me to post the pics of the laser on because it says the file is too big, but it does work and work well. Made specifically for the Assassin laser pointers found on ebay. No support needed for this print. Takes about 50 mins at .35 layer height. 2 of these together were super stable and accurate as well. If yours is too loose or tight, scale a percent one way or the other and try it out... 08/29/2020 UPDATE: after printing in ABS on Original MK2s Prusa, I found that 99.5% scale was perfect. 100 was a little too loose to hold light when it is in off position, 99% was too tight to get the laser in....99.5% took a little twisting but is super snug and the laser can be removed easily if needed. Could be different for you, but just a note to show how specific you may need to scale to get the perfect fit