HK Series Industrial Interchange Series B Brass Hydraulic Quick Disconnect, Female Half, -16 Coupling, 1 - 11-1/2 Female NPT

Buna-N is the seal that comes standard, and it handles hydraulic oil well within its rated range of -40°F up to 250°F. If your setup runs hotter or involves something more aggressive than standard hydraulic fluid, there are alternative seal materials available including PTFE, Neoprene, FKM, EPDM, and Kalrez. FKM stretches the upper limit all the way to 400°F, and EPDM covers down to -65°F on the cold end. Most general hydraulic tool and agriculture applications won't need anything beyond the standard Buna-N, but it's good to know the options are there if your fluid or temps push outside that window.