The new quick connect hose connectors are a step ahead of all the others. Suitable for use with all 12.5mm-1/2" and 15mm - 5/8ths" hose. All internal parts are made from ultra tough engineering plastics for a long leak free life. Secure up to 10 bar, thanks to a triple locking system. The sleeve is easy to use even when wet because of the twin soft touch pads. The hose is firmly connected thanks to barbs that connect with the inside and outside of the hose. Approx: 2.5mm. Ref: UTST649