Zip Pullover purchased from Costco will set you back about $8. In a lawsuit, Lululemon Athletica alleged that the Danskin pullover and other products sold at Costco are illegal knockoffs of Lululemon’s premium activewear.

Lululemon Athletica claims in its lawsuit filed in the U.S. District Court for the Central District of California that Costco has “unlawfully traded” on its reputation, goodwill and sweat equity by selling unauthorized and unlicensed apparel that uses knockoff, infringing versions of its patents.