Search the indicated locations to find both Stabilizers, which permanently increase your weapon reload speed increase.
1. It is sold in the Yard, Trailer save room. Insert five Antique Coins on the Easy or Normal difficulty to unlock it.
2. Complete the hidden Projector puzzle in the Yard to unlock it. Get the Toy Axe from the Attic (accessible through the Kid’s Room after collecting the Snake Key), and place it on the pedestal in the Yard. The Projector puzzle is behind the bushes, to the left of the Testing Area entrance. Turn the Toy Axe so it projects a “7” to open the chest.