Made with heavyweight polypropylene webbing for sturdiness. All collars include D-ring and an adjustable slide buckle. Collar measurements are approximate: Small Collar - 7.5”-11” L / 3/4" W Medium Collar - 10”-16.5” L / 3/4" W Large Collar - 12.5”-21” L / 1" W X-Large Collar - 15”-26” L / 1" W