Use these expanders with collets to adjust the size of your pilot up to .020". Every expanding pilot includes a collet and expander. Use these as replacements for damaged or lost sizes. Fits P-312NX, P-8.5MMNX, P-343NX, P-312NXL, P-343NXL, P-312SX, P-343SX, P312KX, P-43KX or other .312" or .343" expanding pilot.