1/2 NPT to 3/4-16 Male Adapter, Brass. This adapter allows you to install AN-8 hoses to your oil cooler thermostat or any other item with ½ NPT threads. Constructed of forged brass. Complies with MIL-F-18866 Spec. One side of adapter has ½ NPT male threads and other side has 3/4-16 UNF straight thread. 37 degree male flare