20" wheel (20" x 1.75" Tire). Rational designed according to somatology and movement features * Cotterless steel crank. Excellent manganese steel wheel bearing and frame * Extra Thick Alloy Aluminum Rim. Smooth riding wheel bearing. Steel fork with powder coated finish * Large saddle in unique design for extra comfort & safety. Removable poly-nylon guarded rails on the seat * Quick release alloy aluminum lock for height adjustment. Full-sized nylon pedals with chromoly spindles