Madbull Ultimate 3-in-1 Hop Up Chamber for M4/M16 AEG (w/ Shark Bucking)

Madbull Ultimate 3-in-1 Hop Up Chamber for M4/M16 AEG (w/ Shark Bucking) This New Metal Chamber Set have three functions in one 1.The LED Tracer Unit(Optional, Sold separately) 2.Chamber Lock(Is design by Brian Holt) 3.Easy Adjustment Wheel device Metal Hop Up Chamber Unit Set with 60