Can the Friction Knob UMS be attached to a table, bed or wheelchair? Ed Clausen February 11, 2021 18:01 Updated Yes, the Super Clamp allows mounting to flat or round (tubular) surfaces up to 2” in size. Related articles How do I connect a mounting plate to the Friction Knob UMS? How do I make my app compatible with Hook+? Comments 0 comments Article is closed for comments.