HK Series Industrial Interchange Series B Dust Plug, -16 Coupling

The key callouts are that it is an Eaton HK Series dust plug in -16 size, and the HK Series meets ISO 7241-1 Series B dimensional requirements. If your coupler is an HK Series, ISO 7241-1 Series B style in -16, this plug is the intended match.

Buna-N is the standard seal material, which covers most general hydraulic fluid applications and holds up from -40F to +250F. If your system runs something different, there are several upgrade options: Neoprene works down to -65F and tops out at 212F, EPDM handles -65F to +300F and suits water-based or glycol fluids well, FKM goes from -15F up to 400F making it a solid pick for higher temps or aggressive fluids, and Kalrez is also available for more demanding chemical environments. PTFE back-up rings are included in the female socket regardless of which seal material you choose.

It's designed to meet the ISO standard 7241-1 Series B dimensional requirements, so if your coupling also meets that spec, it should fit just fine.