Retaining Ring, Air Cap 0277507
Part Number: 0277507 (Replaces obsolete part # 0275582)
Sometimes this part gets tightened too much so that the air cap can't move. The air cap is designed to "float" to change spray patterns, so it should not be screwed on as tight as possible.
Listed as item number 32 on Titan Maxum II Gun Part Breakdown.