The two movable buckles on the chest and back can be adjusted according to the size of the bust of the pet.  Its durable triangular metal buckles can be pulled firmly. Using foam soft and comfortable handles makes it comfortable to hold even large dogs and long-term traction. It is not easy to fall off for its thick metal plating buckles.    Item Name: Pet Chest Strap Material: Nylon, Foam, Plastic, Stainless Steel Features: Adjustable, Anti-fall, Wear-resistant, Reflective Chest Strap Size Details: [Our Size S] Bust: 30cm-45cm/11.81"-17.72", Chest Strap Width: 1cm/0.39", Traction Rope: 0.6cm x 130cm/0.24" x 51.18", Pet Weight: 1.5kg-4kg (Approx.) [Our Size M] Bust: 40cm-55cm/15.75"-21.65", Chest Strap Width: 1.5cm/0.59", Traction Rope: 0.8cm x 130cm/0.31" x 51.18", Pet Weight: 4kg-7.5kg (Approx.) [Our Size L] Bust: 45cm-60cm/17.72"-23.62", Chest Strap Width: 2cm/0.79", Traction Rope: 1cm x 130cm/0.39" x 51.18", Pet Weight: 7.5kg-22.5kg (Approx.)    Notes: Due to the light and screen setting difference, the itemand 39;s color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.   Package Includes: 1 x Pet Chest Strap Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.