TAC 9 Tube, 700c x 18-23 (27" x 1"). Choose your required length of valve stem. Or any bike tire with same dimensions. It's imperative you maintain proper air pressure with this thicker and heavier tube. See tire manufacturers minimum and maximum pressures on the side of the tire. This tube is a replacement inner tube for any bicycle tire with the same tire dimensions. Be sure to verify the valve type and length. Each tube is quality control inspected at the factory.