n simple terms: this is a wrist brace with a thumb loop (or thumb opening) made by Tynor. You slide your hand in (with the thumb loop supporting the thumb), wrap the brace around your wrist, then secure it snugly with the strap/Velcro system. The brace compresses the wrist area, limits excessive wrist motion (especially flexion/extension/rotation), retains heat (which helps comfort/pain), yet allows you to use your fingers. The materials used (neoprene, elastic webbing, durable fabric) ensure durability and decent support.