S = Width 2.5CM * Length (35-43) CM <br />  M = Width 2.5CM * Length (40-48) CM<br />  L = Width 2.5CM * Length (45-52) CM<br />  XL = Width 2.5CM * Length (52-60) CM<br />  Color:Red，Blue，Yellow，Pink，Black，Green，Orange.<br />   Flashing mode:Long light，Flash， Slow flash， Close( via switch control ) <br />   Battery:2PCS CR2032 button battery -driven (60-80 hours， normal 2-3 months ; battery can be replaceable ， convenience stores or supermarkets are available .)