The Duncan Flipsideâ„¢ features a patent pending ball-bearing spacer system that allows yo-yo players to use either a small OR large ball-bearing in a single model! Based on the original specs of the popular FH Zeroâ„¢, the Flipside features a modern profile with SG Stickerâ„¢ response for unresponsive play. Throw in the included KonKave bearing and you'll be throwing one OF THE best plastic yo-yos ON THE market! EACH Flipside includes BOTH a large KonKave ball-bearing AND a small ball-bearing.