The Pro Spine Kit is an accessory added to two existing Quarterpipes. You must purchase the two Quarterpipes separate in order to use this kit. The Pro-Spine has two coping pieces in place of the deck panel of the quarterpipes to create the perfect spine. Steel is powder coated for maximum durability and grind-ability. This kit can also be added to the side of the Fun Box to allow both sides to be grinded.