SLIK Leveling Unit For horizontal adjustment of video heads, etc. Mounting screw: 1/4 inch. Adapters (included) can be removed to accommodate 3/8 inch. Top (as shown in the 3rd photo, the part that contacts the head): approximately 65mm in diameter. Bottom (as shown in the 4th photo, the part that contacts the tripod): approximately 58mm in diameter. Height: 34mm (excluding screw protrusions). There are scratches on the top (3rd photo). This does not affect use. Operation has been checked. No box or instruction manual. Only what is shown in the photos is included.