Contenders Ready! The Inflatable Gladiator is a great It’s a Knockout activity suitable for children & adults with an inflatable Gladiator Duel bed size of 20ft x 20ft. All participants wear Gladiator protected head guards & use padded bashers to knock each other off the padded platforms. The Inflatable Gladiator duel can be set either on grass or hard surface. The Inflatable Gladiator dual is a good attraction to play and watch at any It’s a Knockout event.