Male coupling galvanised steel ventilation ducting pipe joining connector spigot. Made of 1mm galvanised steel. The couplings are the cheapest on ebay simply because im a sheet metal worker by trade and make them all by hand my self so there is no middle man. These are plasma cut so may have a little burr on the edges If you have any questions or any specific sizes you require please dont hesitate to get in touch and ill be happy to assist. Thank you
eBay