The SMC Swivel is a piece of high performance gear with silky smooth action and a beautiful finish and feel - its exceptional quality is immediately apparent once you pick it up...we’ve seen that most people won't put it down once they have it in their hands! The SMC Rescue Swivel is built around a heat-treated steel axle and a sealed high efficiency ball-bearing to ensure flawless rotation during even prolonged and difficult raises in severe rock, mountain and rescue conditions. The holes are sized to work with rescue carabiners, and allow carabiner lock sleeves to pass through without hanging up. As one of the most compact swivels on the market, it is ideal for confined space rescue and other awkward hauling situations. The sides are smooth and rounded, helping to prevent hanging up on rocks, litters, or other components or structures. All SMC NFPA products are third party tested (by Underwriters Laboratories - UL) as required by NFPA 1983 (2012 edition) standards.