8 in. Silver Heavy-Duty Spring-Loaded Gate Caster with Adjustable Bracket and 200 lbs. Load RatingStark Heavy Duty spring loaded gate casters adjust with surrounding terrain to maintain gate height throughout the opening and closing cycles. These rotating supports work equally well on level and uneven exterior surfaces such as asphalt, brick, concrete, dirt, grass, gravel and pavers. Spring loaded vertical travel to smoothly navigate the terrain surrounding the gate. Rotating supports work equally well on level and uneven exterior surfaces such as