Quality Nylon Rollers: The package contains 1 set of 2"(diameter) x 2.8"(height) rollers, the gate roller position can be adjusted according to the width of the door frame, and the gate roller guide is made of bearings + nylon, the quality bearing steel is strong and durable, and the nylon material can be used very easily. Better to reduce friction and noise, making your sliding gate operation smoother and quieter.Universal L-Shaped Bracket: The universal L-shaped rail mounting bracket is suitable for all sliding door types. The bracket can be modified to face up or down, making it more practical. The L-shaped bracket made of quality steel has good load-bearing capacity and strong resistance to deformation. L-shaped bracket dimensions: 6 x 2 x 2.6 inches (L x W x H).