LCT PBS-4 Tracer Unit (PK-259T)For LCT various designs LCK except AS VAL MRK VAL LGM VAL VSS; These models should be assembled the PK404 LCK 12 ZK 12 ZK 12U LCK 15 LCK 19; Can be compatibled with PK311 M14 to M24 Muzzle Thread Adapter; Support green and red tracer BBs Fits on 24mm CW threads (common on some AK models). Comes with a 24mm to 14mm adapter for the PBS 4 to use with 14mm CCW threads as well.