Rear drum... lever.. this is the LEVER the is attached to the end of the parking brake cable on both sides.. of the hugely used.. common.. 9.5 inch rear drum brakes. PULLS and holds the shoes against the drums.
Often lost .. its a pair set.. only.
Fits but not limited too:
67-81 Camaro
67-81 Firebird
64-72 GTO, LeMans, Chevy Chevelle, Malibu, Olds Cutlss, Buick GS
64-74 Nova, Chevy II
Late 70's Impala.