Dimension Steerer Extender adds 2 to 3-1/4" height to steerer. - Extender clamps to steerer; stem clamps to extender - Adds 2 to 3-1/4-inch height to threadless steerer - Includes top cap and long bolt - 40mm of threadless steerer is required for proper installation - Do not stack steerer extenders; no more than one steerer extender recommended per bike - WARNING: Dimension Steerer Extender is not recommended for use on forks with carbon fiber steerers