GEORGE Black Acrylic Slider Collar S size / 2cm width (43cm) / 8,250 yen (tax included) Unused. Nylon choke collar. This collar tightens when pulled, signaling "No!". It's a tool to communicate commands to dogs who don't understand words, by applying pressure to the neck. Two charms are attached. The charms make a sound when a command is given, and this sound also helps with the command.