Tummala Electronics Pvt. Ltd. Manufactures 4 Wire and 2 Wire Conversion Units. Tummala Electronics Pvt. Ltd. Offers Railway Communication Equipment, Solar Water Heaters and Solar Powered Lighting Systems. The 4 Wire and 2 Wire Conversion Units are Interface equipment specifically designed to enable operation of the control where both 4 wire and 2 wire working is required. This unit can also be used wherever a 4 wire speech circuit is to be interfaced to a 2 wire circuit. The 4 Wire and 2 Wire Conversion Units are housed in a metal cabinet with easily accessible controls. Built in trains and receive amplifiers in the equipment compensate for the losses in the hybrid conversion circuit.