If you have the big EMP grenade (not the one that can go on scars or fy71's), and you left click and hold for about 3 seconds-5 seconds and a enemy is near by it will tell you where to put your cursor to get a direct hit. No this is not a special attachment or special EMP Grenade Launcher you can only get at one point in the game. It can be an EMP Grenade Launcher that falls out of the sky as long as it's normal and not broken, it should do the above. If you have any problems PM me.