[Built-in Spring Design]: Innovative built-in spring design, extends the life of the spring while providing a more beautiful appearance. The built-in spring clamp acts as a shock absorber when gate wheels for wood gate roll on uneven or rough surfaces, reducing stress on gate hardware and extending the life of a gate's posts and hinges [Spring Loaded Gate Caster]: Adjustable spring-loaded bracket with up to 1-3/4 spring-loaded vertical travel, automatically adjusting gate height with the surrounding terrain throughout the opening and closing cycles, effectively preventing gates from sagging to keep the fence line level [Heavy Duty Gate Wheel]: Thick matte black finish plating steel plate and double ball bearing bring strong load-bearing, 250 lbs maximum load capacity for each gate wheel, make it easy to open or close large, heavy wood gates, vinyl doors, metal tubular gates or swing gates. metal [360° Swivel Fence Gate Wheel]: 5-inch aging-resistant rubber caster with 360° rotating top plate, excellent mechanical strength and load-bearing capacity, easily transforms to any direction you want, allows you to spend little force to move the gate safely [Easy to Install]: Heavy-duty universal mounting plate with 3 holes for easily attaching to wooden gates with lag bolts. The versatile hole pattern also allows for easy mounting to a tubular farm gate along a horizontal or vertical gate track, with mounting bolts and screws included