To activate your Electro Luminescent Zip Up Hoodie press the button located on the battery housing located on the inside of the jacket for 3 light functions Blink slow flash steady light Note . Item must be hand washed and hang dried Remove the battery house before washing Sizes are unisex meaning a Large for a male may run a bit bigger for a female Electro Luminescent Zip Up Hoodies are available in MD LG XL please see our other listing for addtional sizes Comes ready to use with 2 replaceable AA Batteries Specifications . Size Small. LED Color Blue