Summary Lets you attach a 1/2" poly hose to a pump having a 8.6mm / 0.34in barbed connection. Instructions I created this so that I could attach a 1/2" poly hose to a pump that had a smaller barbed connector. I put some super glue on it and slid it over the barb on the pump. Be careful not to break the pump's smaller barb off when attaching the hose as they are not very strong. Like most functional parts, print it with 100% infill.