Secure Meters Ltd. Offers Liberty Dual Register Prepayment Meter. Secure Meters Ltd. Is an ISO: 27001 and ISO: 14000 certified company. Liberty Dual Register Prepayment Meter is an integrated meter for measurement of both mains supply and DG supply. This meter with associated system helps in effective revenue management. Meter distinguishes the source of supply and deducts the amount according to respective tariff. Liberty Dual Register Prepayment Meter provides convenient payment options to the consumer and eliminates all the hassles associated with post paid system. It is applicable for commercial establishments, residential complexes, temporary connections, educational institutions, industries and for complexes with full and partial load back up.