Airsoft kit ASKU CYMA:1) Two options of handguard (155mm and 215mm)2) Gas tube3) Two options grips4) Picatinny rail5) DTK KochevnikFor installation, you need bolts and cakes m3 and m4. There is a video instruction for installation. Adjust the scale before installing the silencer, first print the threads (PLA scale 98%)