This is a DIY kit,need buyer to assemble it. LM117 / LM317 three terminal adjustable positive voltage regulator IC, audio effect than the 78xx, 79xx series regulator much better, is a convenient and widely integrated voltage regulator block. The output voltage range of 1.2 volts to 37 volts to provide more than 1.5 amps, a variety of built-in protection circuit overload protection, protection of the safe areas, very easy to use, For preamp, amp, decoders, electronic production, such as adjustable high-precision power supply. Parameter:DC input: 5-40 VAC input: 3-27 VOutput DC : 1.5-37 VMaximum current: 1.5 AMinimum differential input and output: 3 V (input, output, preferably within 10V, 3-5V best, this is a linear IC, power consumption is proportional with the pressure, increase the pressure too large 317/337 power required increase the heat sink, the maximum recommended voltage differential can not exceed 20V)Complete high voltage output board supports up to 37V output voltageWherein lm317 lm337 is disassemble products, general product outward, performance is good. Package included:1x LM317 LM337 Linear Voltage Regulator Power DIY Kits