Gibson owns for the mark EXPLORER in connection with guitars. Gibson also owns for the Explorer's headstock design, and for the Explorer's body shape design. However, the enforceability of the latter two design trademarks is uncertain in light of Gibson's unsuccessful lawsuit against PRS Guitars for allegedly infringing Gibson's Les Paul shape. In 2005 the United States Court of Appeals for the Sixth Circuit ordered summary judgment against Gibson in that action, on the grounds that there was no evidence to support a finding of likelihood of confusion.