The parts of the OS Kit are housed in a tin with a magnetic base that keeps all the parts sorted. On the inside of the lid is a to-scale image of all the included parts so you can easily identify each spare part. From screws to pins to detents, the RISE OS Kit contains spare parts that can be impossible to find if dropped.Features :Buffer Retainer (x1)Buffer Retainer Spring (x1)Anti-Walk Pin Screws (x2)Takedown and Pivot Pins Detents (x2)Takedown and Pivot Pins Springs (x2)Safety Selector Detent (x1)Safety Selector Spring (x1)Firing Pin Retainer (x1)