1. LED Power:4pcs CR2016 Cell Button.2. 3 Light Modes:Continuous on,Slow flashing,Fast flashing(with switch to select)3. Material:nylon4. Size：XS/S/M/L/XLXS width 1.5cm telescopic range 32-39cm (the battery case is silicone battery is CR2016*4)-- Bust: S 32-40cm-- Bust: M 38-50cm-- Bust: L 43-60cm-- Bust: XL 50-67cm

http://olla.gr/double-sided-led-light-pet-harness-nylon-cat-dog-chest-strap-leash-size-m-blue/