De or het pocketvering?

The correct Dutch article is:

de pocketvering

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

How to use pocketvering

the pocketveringde pocketvering
this pocketveringdeze pocketvering
that pocketveringdie pocketvering
our pocketveringonze pocketvering
your pocketveringjouw pocketvering
every pocketveringelke pocketvering
which pocketvering?welke pocketvering?
a big pocketvering / the big pocketveringeen grote pocketvering, de grote pocketvering