Makita part 257075-2 — Ring 9 (genuine Makita). A small but critical hardened metal retaining ring sized for 9 mm pins, used to secure the clamp and front-vice assembly on Makita chain mortisers (notably model 7104L). It slips onto the 9 mm locating pin to lock the clamp/washer stack in place and is sold individually as the replacement ring you need to restore the vice/clamp linkage to factory condition.