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