This Ariston Andris Discharge Tundish KIT C is designed to visually indicate when a hot water system over-pressurizes. Water is discharged via the 6 bar pressure relief valve, and the tundish makes this discharge visible. It is specifically for use with Ariston Andris R water heaters and features a 15mm x 22mm connection. This kit is advisable to use whenever the pressure relief valve is installed.