this is the short tower, the tall optic slides into this part. the tall tower is held in place by the tower base.
the height of the tower is about 2"
if building a set of ecto goggles using our parts you will need
1 short optic,
1 tall optic
1 tall tower
1 short tower
2 tower bases
4 thumb screws and bases
and a mounting frame which is optional.