“This Harmony RUM varistor has a control coil voltage of 240V AC/DC.””It has a light weight and it is compatible with socket RPZ with 3 and 4 changeover contacts.””This protection module enables safety to your relay which helps to protect both people and system from electrical shock.””Simple modular design facilitates post installation servicing, modification and adaption of machines by non-specialists.””It can be matched with any relay socket from RPZ and RUZ ranges.”