#25 roller chain is a 1/4" pitch ANSI Standard roller chain designed for light-duty or space-confined applications. It's the smallest size roller chain on the ANSI spectrum but offers ample performance, strength, and durability for its small form factor. The selection includes standard carbon steel, stainless steel, and nickel materials. Notably, the #25 roller chain does not contain rollers; instead, it has bushings that come into contact with the sprocket.