The Luth-AR Carbine Lock Ring/Castle Nut secures the buffer tube to the lower receiver and prevents the end plate from rotating on AR-pattern rifles.
- Part Type: Castle Nut/Lock Ring
- Compatible Firearms: AR-15, AR-10, and AR-pattern rifles with mil-spec buffer tubes
- Material: Steel
- Finish: Phosphate
- Installation: Professional recommended (requires torque wrench, armorers wrench, and staking)
- Includes: (1) Castle nut
