This is a Haltec TC-50 one-piece rubber O-ring style rubber tube for mounting hard to seat 16.5 inch through 17.5 inch radial or bias truck tires. As the tire is inflated, the lubricated bead seater forms a seal between the rim and tire allowing the air pressure to force the beads into the rim flange. As proper pressure is reached, the bead seater slides out and over the rim. The bead seater is reusable and a must have for any tire shop. Haltec is a leading manufacturer of inflation systems and maintains its leadership position as a major manufacturer of specialized tire valve systems.