Yeeco TY100 LM317 Linear Full-Stage Voltage Regulator Volt Regulated Board Fan Speed Controller Control Switch Governor Governing LM317 linear full-stage voltage regulator volt regulated board It is has heating, over-current and short circuit protection function Input voltage :DC3.25-15V Output voltage: DC1.25V-13V (maximum dropout 2V) There is LED indicator on this converter board,the module can be use as an fan speed Controller Control Switch Governor This converter board come with 2 lines with plug and potentiometer knob,easy to connect