The H9000 D.I.Y. Butterfly Pipe Corner Kit allows the possibility of making frames of any dimension. The kit comes complete with 4 corners, 2 straight pipe connectors with ears and 2 straight pipe connectors without ears. The nominal bore of this flexible butterfly pipe corner kit is 1.5 inches/3.8 cm. Aluminum Speed rail piping is what is used to customize the size of this butterfly kit. The outer dimension of the corners and pipe connectors is 1.9 in/48.3 mm. This size is very popular in the UK and the European markets. 1.5 in speed rail can be found in the North American market but the preferred size is 1 1/4 in. Recommended Accessories: H6BAG, D400, A3058CS, A3059CS, 087WBK, A5036CS, A5042CS, A1045CS, A1045B, G200-1