Canon Extension Tube EF 12 II, Black, 66 g, 80 mm, 75 mm, 70 mm, 149 g Canon Extension Tube EF 12 II. Product colour: Black. Weight: 66 g. Package width: 80 mm, Package depth: 75 mm, Package height: 70 mm https://www.the-digital-picture.com/Reviews/Canon-EF-12mm-Extension-Tube-II-Review.aspx The Canon EF 12mm Extension Tube II is slightly smaller than half the size of the Canon EF 25mm Extension Tube II. The 25mm review is applicable to the Canon EF 12mm Extension Tube II as well.