Victory Athletics Spring floor, available as Semi Assembled (DOES NOT INCLUDE MATS) Two layers of Baltic Birch/Velcro system & 4" springs with pop in retainer cap. Each bolt is held in with VICTORY'S EXCLUSIVE EPOXY. Each spring is secured with a Bolt instead of a screw to ensure each spring assembly will stay attached. Springs are made out of piano wire. Each performance top has 50% more hook & loop then our competitor.