Shock Doctor, the U.S. brand of protection equipment including mouth guards, footbeds and more, has acquired XO Athletic, another specialty company for protective gear, for an undisclosed amount. The acquisition provides access to patented technologies owned by XO along with retail efficiencies that are supposed to benefit both brands. Shock Doctor intends to maintain XO Athletic as a separate brand based in Union, New Jersey. Back in 2008, the two companies quarreled over an alleged patent infringement by XO Athletic. Last March, Shock Doctor itself was acquired by Bregal Partners, a private equity company based in New York City. The deal then included the Cutters glove brand that Shock Doctor bought in June 2012.