THE LIBRARY SHELF
Size & shape
Clip length is not a jaw-opening measurement
Keep the maker outer dimensions separate from an unknown opening.
Large and jumbo are names, not a shared size standard
A product family and exact dimensions make a size label useful.
A claw clip and a French barrette use different mechanisms
Do not compare every hair accessory as an interchangeable clamp.
A travel-case check needs three outer dimensions
A bounding-box calculation is narrower than a real packing or closure test.
Teeth count does not calculate a guaranteed holding capacity
The unknown useful opening stays separate from visible geometry.