The 1 - 5/8" landing strip side release collar adjusts for a neck size of 19.5" to 31.5"; it is suitable for German Shephards, Bulldogs, St Bernards, Bouvier and similar size breeds. Woven reflective thread stitched into high grade nylon webbing. Ergonomic contoured components ensure a snug fit; box stitched joints for added strength and a quality finish.