Connections to unvented cylinder are either 3/4" or 1" and a suitable coupling or elbow to connect that to copper pipe is required. Cylinders are now being fitted with 1" and a suitable coonector is a Pegler or Prestex PX 45 or PX 46 depending on whether it is male or female. Currently Screwfix only has: 22mm x 3/4" Female 5411G PX46 22mm x 3/4" Male 5468G PX45 28mm x 1" Male 2936G PX45 You do stock the straight coupling 22mm x 1" in both male and female. Please can you add: 22mm x 1" Male PX45 Link to Pegler 22mm x 1" Female PX46 Link to Pegler