A.R.M.S. - Laser Pointer / Muzzle Flash LED Holder
A.R.M.S - A Reconfigurable Maker's Shooter
This part works for mounting either LEDs (for muzzle flash) or 6mm laser diodes on your ARMS tagger.
Designed to suit the Mk.1 Shooter ( http://www.thingiverse.com/thing:454862 ), but I intend to make future (larger) guns compatible also.