01. BT -4 Master Parts Kit

02. BT Folding Foregrip 3 Position (Fits Picatinny Rails)

03. BT 4 Spring Kit

04. BT - 4 Player Parts Kit

05. BT-4 Double Trigger Kit with Guard

06. BT Delta Elite Upgrade Kit

07. BT4 Electronic Frame

08. BT SA-17 Spring Feed Magazine

09. BT 16 Barrel Bipod (Req's BT 16 barrel kit)

10. BT-16 Barrel Bipod Adapter