Spalding IP556 iHoop Portable Basketball System - 54" Glass Backboard Full-tempered glass 54- by 1/4-inch backboard is enclosed in a steel backboard frame Spalding's exclusive ScrewJack lift system makes rim height adjustments easy The Arena Slam breakaway rim is designed to flex when pressure is applied, helping to relieve stress from the backboard during game play. Tip & Roll portability mechanism with two oversized wheels make moving the iHoop quick and convenient. Features two 3-inch speakers and a 5-inch subwoofer