Part Number: 051138-21326-8 (Kit: air regulating) Part Number: 051138-21478 (Socket: 1/4in body,3/8in mpt) Part Number: 051138-21511 (Adapter: filter) Part Number: 051138-21565 (Respirator: half-face,sm) Part Number: 051138-21571 (Respirator: half-face,med) Part Number: 051138-21573 (Respirator: half-face,md) Part Number: 051138-21577 (Respirator assy.) Part Number: 051138-21579 (Respirator: half-face,lg) Part Number: 051138-21674 (Cartridge organic vapor) Part Number: 051138-27786922318 (No description) Part Number: 051138-28880 (Cartridge: acid gas) Part Number: 051138-28911 (Use 051138-28991=27) Part Number: 051138-28991 (Pad petroleum sorbent) Part Number: 051138-29008 (Earplug foam org 200bx)