Contains Springs that are commonly used or sprung across the room/field. Includes: Firing Pin Retaining Pin (x2), Extractor Spring Assembly (x2), Detent Selector (x2), Selector Spring / Ejector Spring (x2), Buffer Detent (x2), Buffer Detent Spring (x2), Detent Spring (x4), Take Down Detent (x4) & Extractor O-rings (x2)