Integrated spring design: Innovative integrated spring design extends the life of the spring while providing a more attractive appearance. Built-in spring clamp acts as a shock absorber when wooden gate wheels roll over uneven or rough surfaces, reducing stress on gate hardware and extending the life of gate posts and hinges. Spring-loaded gate roller: Adjustable spring-loaded support with up to 4.5 cm of vertical travel, allows automatic gate height adjustment to surrounding terrain during opening and closing cycles, effectively prevents gates from sagging to keep the fence line level. Heavy-duty gate caster: Heavy-gauge matte black plated steel plate and dual ball bearings provide strong load support, maximum load capacity of 200 lbs per gate wheel, making it easy to open or close large, heavy wooden gates, vinyl gates, metal tube gates, or metal swing gates. 360 swivel caster: 4-inch aging-resistant rubber caster with 360-degree rotatable top plate, offers excellent mechanical strength and load capacity, easily turns in any direction with minimal effort for safe gate operation. Easy to install: Heavy-duty universal mounting plate with 3 holes for easy attachment to wooden gates using lag bolts. The versatile hole pattern also allows for simple mounting to tubular farm gates along horizontal or vertical gate tracks, includes mounting bolts and screws.