Aggressive : UNITY skates feature lace lock closure system, a interchangeable frame. Unity is ideal for both Vert and Street skate and for those in search of high performance and durable construction. Size : 4-12 Shell : BASF PU 64D Chassis : Du-pont Zytel 8018 Wheels : 62 x 24mm 90A by Hyper Bearing : Abec-3 Hi precision bearing Soul plate : Du-pont Zytel 8018 Liner : Breathable memory foam