Look, I have to go , 6 letters
A weather strip may fit into it, 5 letters
Groove for a letter-shaped bolt, 5 letters
Letter-shaped aperture, 5 letters
Letter-shaped opening, 5 letters
Letter-shaped opening for a bolt, 5 letters
Letter-shaped opening in some pistons, 5 letters
Letter-shaped track, 5 letters
Letter-shaped workbench groove, 5 letters
Mounting feature for shop machine parts, 5 letters
Opening for a letter-shaped bolt, 5 letters