1 input: DC 4.5 V-7 V (input voltage must be more than to output voltage high 1 V above.) 2 output: 3.3 V, 800 mA (load current can `t more than 800 mA) 3 : PCB size:8.6* 12.3 mm Attention : 1: Boost modules or buck module indicate the operating voltage, Please donot exceed operating voltage , or it will be damaged easily ! 2: Boost module output voltage can only be greater than or equal to input voltage, cannot be less than the input voltage! 3: Buck module input voltage must be higher than output voltage of 1.5V or 2V, otherwise it can not output enough power! 4: Automatic Adjustable Boost or Buck module has start voltage and limit working voltage, Please donot exceed them , or it will be damaged easily ! 5: Cannot reverse polarity , or it will be short circuit, or will be born easily !