Rubber Grommets available in large or small sizes. Small grommets require a 16mm hole to fit into and work with 10mm supply tube. Large grommets require a 22mm hole to fit into and work with 13mm flexible tube.
Hydor Theo water heaters are among the safest and most advanced water heaters on the market. Theos aer shatter proof and feature thermal cut off technology to prevent the units from burning out should your tank level run too low.