Original DeWalt NA017407 — genuine DeWalt check valve designed for use in DeWalt cordless air compressors (for models DCC1018X1 / DCC1018T1 / DCC1018N / DCC1020N /  DCC2520T1). 

This one-way valve prevents tank-to-pump backflow and installs in the compressor’s air plumbing: inlet uses a 12.7 mm NPT thread (1/2") and the outlet is a 6.35 mm hose barb (1/4") for the supply hose.

A direct-fit, original DeWalt replacement that’s ideal when the in-tank/check valve has failed — a straightforward swap to restore proper pressure retention and pump protection. This is listed among DeWalt spare parts for the DCC2520T1 cordless air compressor.