These right angle clamps work on rods from 1/2" to 3/4" (12.7 to 19 mm) diameter and are ideal for attaching Glas-Col overhead stirrers to a laboratory stand (item #21057).
This heavy-duty 90° clamp shown here is designed to be more user friendly. It has larger knobs that make hand tightening easier and provide sufficient pressure to hold rods securely and is recommended for most of the stirrers and stir testers available on this site.
We don't have a picture of the light duty clamp. It weighs only 0.1 lb compared to 1.0 for the heavy duty. If you're not ordering for a Glas-Col unit, consider the 22025 or 22021-A clamp holders instead.