Red vapour tanks are specially designed for campervans, caravans, motorhomes and any other RV vehicles as they provide gas in vapour phase. The tank can be safely refilled trough dedicated filling point at every Autogas LPG service station. The valves starting from the left are: Manual outlet valve, thread without adapter: 1/4" NPT, with adapter: W21.8 LH over pressure relief valve (PRV) - in case of sudden pressure increase (over 27 bar) the excess gas is released to the environment gas level float with mechanical gauge filling valve with 80% cut off valve (OPD), female thread without elbow: 3/8" NPT, with elbow 3/4" UNF JIC Specifications Diameter 300mm Length 1085mm Tank weight 23.4kg Usable capacity 56L (29.12kg) Full tank weight 51.4kg