The Daikin-McQuay GCA500015A Coupling is a vital component utilized in HVAC systems to connect shafts and transmit power between rotating equipment such as motors, pumps, and fans. For flexible compatibility, this coupler has a 1/2-inch adapter and two diameters: 1.25 inches on one end and 5/8 inches on the other. https://www.partshnc.com/daikin-mcquay-coupling-gca500015a