This set includes 12 black nylon garage door rollers built to replace worn, noisy existing components. Featuring a 4 in. carbon steel shaft with dual enhanced nylon wheel construction, these rollers absorb vibrations and minimize metal-on-metal contact to deliver whisper-quiet, smooth operation. They come equipped with 6200-2 RS bearings and double-wall bearing caps, which add extra protection to the bearings and help extend the product's overall lifespan. Sized at 1-13/16 in. in diameter (standard 2 in. class), with a 4 in. STEM length and about 0.6 in. thickness, they fit most 2 in. garage door tracks and work with a wide range of residential and commercial garage doors, including automatic and wood models. Installation is straightforward with basic hand tools, making them ideal for DIY garage door replacement projects.