UTV Tech Pro-Tek HSS Swing Arm Armor - Black 521132 The Pro-Tek High Strength Steel (HSS) Swing Arm Armor gives you unmatched protection for your Swing Arms. Pro-Tek Armor products manufactured from HSS offer superior protection against gouging, peeling and denting making them the toughest protection on the market. The HSS steel we use for our products is three times stronger than standard steel and five times stronger than aluminum. Dont settle for less and compromise the integrity of your stock swing arms.