- XS =Width 2.0CM *Length （36-41）cm
- S = Width 2.5CM * Length (42-44) CM
- M = Width 2.5CM * Length (45-48) CM
- L = Width 2.5CM * Length (49-52) CM
- XL = Width 2.5CM * Length (53-58) CM
Flashing mode:Long light, Flash, Slow flash, Close( via switch control ) Battery:2PCS CR2032 button battery -driven (60-80 hours, normal 2-3 months ; battery can be replaceable , convenience stores or supermarkets are available. Waterproof, this product is suitable for dark environment or walk the dog at night , outdoor and pet movement through the bright fiber optic light.