Surefire Z2 combat ring replacement

Surefire z2 combat ring replacement, print using TPU. Use the second file for a fitting tool, print this is ABS/nylon or whatever non-tpu filaement, you have to remove the o rings on the tail cap and slide this down the tailcap threads. Then force the tpu ring over this tool to give you enough leverage to force it onto the actual ring slot. For TPU 95A I did 99% size and 7% infill to have enough give in the material to force it into the slot with the tool. Make sure you lube up the tool with silicone to allow the rings to slide over.