De or het klemring?

The correct Dutch article is:

de klemring

Rule Words ending in -ing: almost always de. See the rule

How to use klemring

the klemringde klemring
this klemringdeze klemring
that klemringdie klemring
our klemringonze klemring
your klemringjouw klemring
every klemringelke klemring
which klemring?welke klemring?
a big klemring / the big klemringeen grote klemring, de grote klemring