This product is supplied with an additional union of the same colour and width free of charge.Our lengths of aluminium gutter are made from high quality, 97% recyclable aluminium alloy. This length in particular measures 125mm width across the top excluding the beaded rim, and 500mm in length. We also stock a smaller aluminium half round system with a 114mm width.When joining aluminium gutter lengths to unions and other fittings, the process must be completed by injecting ARPand#039;s unique 3923 sealant after said fittings have been clipped into position in order to ensure a secure fit.For a full demonstration on how this product is joined to a union and other aluminium gutter components, check out our aluminium union jointing tutorial video.