Product Description Features Short (2"). Requires 3/4" bit. Takes 1/2" screw. Use in mortar & concrete. Zinc. Box of 8. Box of 8 Specifications Dimension: 2.6" H x 3.3" W x 4.3" L Weight: 1 lbs . From the Manufacturer Provides secure anchorage of lag screws in concrete and the mortar joints of block and brick. Short lengths may be used to shorten drilling time. Four way expansion insures a tight grip and prevents over expansion. No lubrication is required.