Where the wear actually shows up
A tub sees water and shampoo residue every day it is used; a gasket that looked fine in January can be cracked by summer. Arm clamps take a different kind of punishment — repeated tightening and loosening across dozens of dogs a week wears the threads and the jaw faces long before the steel itself gives out.
We stock the clamp and the drain kit as the two parts we see fail most, sized against the measurements below rather than against a table or tub brand name, because two tables from different manufacturers can share the same edge thickness.