Dogs My Love Adjustable Nylon Martingale Dog Collar Semi-Choker 1.25" Wide Fits 16.5"-21" Neck Strong and durable adjustable martingale collar with geometric red pattern on black background. Collars are measured 23" all the way open for largest setting; it measures 16" in closed position for smallest setting. Can be adjusted to fit its 16.5 to 21 inch neck circumference - please measure dog's neck before you order. Very comfortable and light 1.25" wide collar - perfect choice for daily walks. Features nickel-plated hardware and heavy duty D-ring. Built to last.