Features: Made of high quality material, sturdy and durable to use. All finishes are non-toxic, safe and environmentally friendly. It effectively reduces the noise in the garage with this nylon roller and extends its service life. No more rattles, squeaks or bangs when opening or closing.10pcs rollers are included in 1 set, very easy to install and . Standard size: 3.5" long shaft, 1.8" wheel diameter. Specification:Material: Iron + NylonColor: as the picture shownMaximum load: 350N(35kg)Size: 4.5*4.5*11cm/1.8*1.8*4.1inch (approx.)Note:Please allow 1-3cm error due to manual measurement, and make sure you do not mind before ordering. Please understand that colors may contain chromatic aberration as different placement of photos.