Stem bumpers are typically used on the bottom of round based swivel outdoor, pool or patio chairs. Stem bumpers keep the round base of the patio chair from siting directly on the ground. In other words these are chair glides for round base chairs. Most of this outdoor furniture use 6 to 8 stem bumpers per chair. These stem bumpers are curved to match the shape of the patio chair base. Round patio chair glides and stem bumpers are sized to fit common patio furniture chair.