Three-position earmuff can be worn over-the-head, behind-the-head or under-the-chin. Includes crown strap required for under-the-chin or behind-the-head wear. Lightweight, durable plastic construction is non-conductive. Features large ear cup openings with foam-filled cushions, replaceable foam cup liners and take-apart assembly. NRR 20 (over-the-head), NRR 22 (under-the-chin) and (behind-the-head). 24/Case.