The double pitch sprocket is a sprocket used with a double pitch chain; The double-pitch chain is derived from the short-pitch precision roller chain for GB/T1243 transmission, the pitch is twice its size, and the rest of the interchangeability is the same; Double pitch precision roller chain and sprocket are suitable for mechanical transmission and conveying; Two-pitch precision roller chains and sprockets are used in situations where the power and speed transmitted are relatively lower than the basic chain from which they are derived. Double-pitch chain and sprocket label, is in the GB/T1243 basic chain number in front of the number "2" composition, conveying with double-pitch precision roller chain, when the use of large diameter roller (d7), then add the word tail L after the original label.