Superb quality custom made tool from Echigoya Japan. 

The finest barrel nut and buffer-tube cap tool available for the TM NGRS HK416 & 417 series. 
This tool is required to tighten or remove the barrel nut and buffer tube end cap on all TM NGRS HK416 models, it is precisaly made and superbly finished so will minimise scratches and tool marks leaving your Recoil in excellent condition after work.