Provides a comfortable grip for holding cases during case trimming and chamfering sessions. Install into all popular priming tools that accept Auto Prime shell holders including our Lee Auto Prime and Auto Bench Prime tool (priming tool sold separately).Specifications and Features: This adapter allows you to rapidly trim brass to the appropriate length or chamfer the inside and outside of the case neck, and rapidly switch to the next piece of brass. This new adapter greatly improves the speed of switching between each piece of brass. No more loosening up the knurled shell holder between each piece of brass. Use in conjunction with your case length gauge and knurled shell holder, cutter with lock stud and chamfer tool.