Guarder 1st Steel Hop-Up Kit for KSC/KWA MAGPUL M4/LM4 GBB Rifle GBB Rifle Metal 90mm Outer Barrel with

Metal 90mm Outer Barrel with 190mm Steel Inner barrel

air-cocking bolt and trigger box

G&P MK23 Electric Drum (Deluxe Set)  1200rd Capacity in Box Magazine  Drum Rack Material: Steel  Nylon Fiber Housing Magazine  Suitable for G&P U

Velocity: 110-116 MPS [360-380 FPS]

APS Rhino Iron Spring Loaded Flip-Up system Front / Rear Sight

Guarder 1st Steel Hop-Up Kit for KSC/KWA MAGPUL M4/LM4 GBB Rifle GBB Rifle Metal 90mm Outer Barrel withGuarder 1st Steel Hop Up Kit for KSC KWA MAGPUL M4 LM4 GBB Rifle Steel Plastic Cooper Rubber Construction Hopup Gel made by 70 Silicone Gel Steel Hopup Round For KSC M4A1 & KWA MAGPUL GBB 1st Version 2nd Version Must Change the inner Barrel, You can Choice Guarder Inner Barrel Series: GUARDER TN 21TN 22TN 23TN 24 As always, upgrading AEG require necessary skill & technique to dissemble the gearbox, consult expertise if needed