100% Makrolon polycarbonate shell / Reinforced aluminum internal frame. Mounting system converts to mini-workstand and allows easy re-assembly and fine tuning. Drivetrain cover protects crankset chain and rear derailleur from scratches and grease stains. Protective sleeves and frame pads prevent abrasion on frame from other components and helps keep them secure. Includes 2 wheel bags (Tire size up to 26 x 2.35 or 700 x 40C). Four bumpers on each side protects case from ground contact when opened. Inner mesh pockets keep tools and gear organized. Padded foam case offers impact protection. Four large 60mm multi-directional wheels and carry handle for easy transportation. Front: Compatible with QR skewer or 12 mm x 100 mm thru axle (Road bike disc). Rear: Compatible with 130 / 135 mm QR skewer or 12mm thru axles. Not compatible with 27.5` & 29` MTB bikes