Front 20+rear 24 or front 18+rear 21 G3. (G3 style hubs is 18/21 G3 holes).(one front wheel and one rear wheel and 1 pair skewers). White or black color bladed spokes, Stainless steel material, when you place your order, please in order "note" tell me your need color of the hubs and spokes. Please choose your favorite hubs, black / red color, can use for 8/9/10/11 speed SHIMANO/SRAM freewheel, and include skewers, if you need use for CAMPAGNOLO freewheel, please in order "note" tell me. Can do with basalt brake surface. Approx Front wheel 0.76kg(tubular), Rear wheel 0.96kg(tubular). Passed Europe EN14781 Standards and the JAPAN JIS Standards.