This holder bag is suitable for most portable oxygen tank sizes. Crafted with a durable, water-resistant polyester material, it features a reinforced base for increased sturdiness and a soft, reinforced lining. The holder bag also has six 11.5 mm hose outlets and conveniently-padded, adjustable shoulder straps with a chest strap for comfortable wear. Additionally, it features a zippered pocket on the exterior for storing small items. This tank holder also comes with a 60-day guarantee. It's designed to fit M2, A or M4, ML6, M9, B or M6, M7, and C cylinders up to 11” in height and 4.38” diameter and is machine washable.