The Tetra Universal Envelope Arm Sling is a deluxe sling made of cotton duck material in a denim color with an open-ended “D” ring design. Adjustment from pediatric to adult sizing is achieved with Velcro® strips inside the sling. Beneath the “D” ring a swatch of foam peels off to reveal the hook portion of the Velcro®. The extra long portion shown inside the sling is the loop portion. By exposing the hook, the desired length is attained by folding the sling back on each side and attaching the hook to the loop area. Strap adjusts with buckle in the back portion and Velcro® through the “D” ring in the front portion. The sling comes with a shoulder pad. One size.