Inner diameter bottom: 8.1mm, inner diameter top: 4.5mm, length: 29mm. Fits the original Daelim Daystar VL125 carburetor. At the bottom inside the hole it doesn't have the 'burr' that is in the original rubber and it 'snaps' nicely on the carburetor (in the special groove of the carburetor) but overall it is a git.