SMAKN&reg; LM317 337 Dual Power Supply Adjustable Module &plusmn; 1.25V to 37V 1.5A Converter Product Name: Dual DC Voltage Regulator. Product Dimensions: 62 mm * 51mm * 30mm (L * W * H). Input voltage: AC or DC 3-40V. Output voltage: dual DC  1.25-37V. Output Current: positive voltage 1.5A, 1.5A negative voltage.