The term DECK UNITS can be solved by the crossword solution CARDS. CARDS are typically rectangular pieces of paper or thin cardboard, usually 3.5 inches by 2.5 inches, that have a design on one side and are blank on the other. They are used for a variety of purposes, including playing games, writing messages, and collecting information. CARDS are often used in decks, which are collections of CARDS that are shuffled and dealt out to players.