Vesta TU series are conceived for durability and long use. The bodies for the wole series are in die-cast aluminium while bowls and setting knobs are made in special polymer for high resistance. For more durability, metal bowl versions with prismatic indicator are available for the TU-3, TU-4, TU-4H and TU-5 series. Finally in order to add more strenght and better output control, pressure regulators are operated by an acetal polymer piston with NBR lip seals.