Tissue Brand Originally Used to Filter Gas Masks

This page is the CodyCross answer for the clue below from Top Secret, Group 2082, Puzzle 2 (Hidden Earpiece).

Question is: Tissue Brand Originally Used to Filter Gas Masks

and the answer is: KLEENEX

Word Meaning:

KLEENEX — (Canada, US) A disposable tissue.

Definitions from Wiktionary.