The quarter-turn fastener that holds a TK series cabinet panel closed. Small, inexpensive, and the sort of thing that goes missing during a service — worth ordering a spare or two while you have other parts on the way.
Teco is made in Italy and its spare parts are model-specific — check the model plate on the back of your unit before ordering. See the full Teco range, including the Teco TK aquarium chillers themselves.

