Tube, 700x20-25 ( 27x1 ), 48mm SCHRADER Valve. Replacement tube for Fixie, single speed, road or hybrid. Works on any bike with same tire dimensions and valve type. 2 Tubes New In Box 700x20-25 (27x1) ISO 622 48mm Schrader Valve Be sure the tire bead is seated evenly all around the rim by first adding a little air to the tire, checking the bead on both sides and if beaded properly continue filling air to the correct pressure as stated on the tire. For the health of your tire and tube always maintain the proper air pressure. See the side of your tire for minimum and maximum pressures.