Cley Films demonstrates how to install Fiber Optic Sights to TM/WE/E&C Glock airsoft gas blowback pistols in this video. Some patience is required as the video is a bit blurry... "In this video I am going to demostrate how to replace the  stock sights of yout Tokyo Marui (TM) / WE Tech / East & Crane (E&C) Glock Airsoft Gas Blowback Pistol with Fiber Optic Sights. The fiber optic sights I am going to use in this video is manufactured by WE Tech and is dropin fit for my E&C Glock 17 Gen5 Airsoft Pistol."