NOTE: this connector is very small, please don't purchase it for 1'' post, its only compatible with 3/4" shelving poles, it will fit H*per T*ugh metal shelf from W*lMat. OUR wire shelving pole connectors are constructed of metal. They are double male threaded connectors which are used to connect two poles together to assemble the shelves. Simple to install and remove. Universal size/ fits most 3/4 threaded posts. Due to that there is post thickness difference on the market, like 1mm and 1.2mm for 3/4, there maybe situations that it won't thread based on the post thickness, under this situation, with a little extra tape on the top end would help get a tight seal.