Each 47mm Adams suction cup has a weight loading of 3 pounds (1.36kgs).
These strong gripper suction cups have a long neck with protruding nubs around their circumference. They are great for posters which are 3mm in thickness and where a quick fixing is preferred to using a top pilot hole suction cup with a clear screw or brass nut fitting.
The suction cup can be pushed into a drilled hole of a poster or sign and the nubs will ease back out to grip the back of the poster (see technical drawing image for dimensions).