Polypropylene connectors and are the most economical and simplest way of joining your polypro hoop together. They can be fitted by friction or rivets. Add a metal push button clip to make your hoop a coil down travel hoop. These particular connectors are made using the Imperial system of measurement and therefore fit best in tubing that is manufactured in inches rather than millimeters.
Connector R 15.9mm (5/8″) OD x 10cm (for regular polypro tubing)
Connector S 12.7mm (1/2″) OD x 10cm (for skinny polypro tubing)