This coupling allows you to quickly disconnect your cooling system without any fluid loss. At only 1. 60 oz. , this coupling is 54 percent lighter than the traditional 3. 49 oz. steel male coupling half. The thread connection is 1/2 in. NPT. It's safe plumbing maintenance made easy from Aeroquip.Ian Boettcher Race Parts offers Aeroquip Steel Female Radiator, Cooling Quick-Disconnect Coupling FBM3113 at low everyday prices. Be sure to check out all of our products from Aeroquip including Aeroquip Radiator Fittings.