Open Chassis Model
On smaller models of open chassis styles, the sill support secures to the underside of the air conditioner with two type A screws. The bolt rests on the outer sill and is adjustable to create the appropriate tilt.
On larger size open chassis models, the sill bracket is secured to the outer sill and the support bracket is secured to the underside of the air conditioner. A carriage bolt secures the sill bracket and the support bracket together. Once the air conditioner is tilted appropriately, the carriage bolt is tightened on the sill bracket and support bracket to secure its position and prevent it from moving.
On fixed chassis models, the sill bracket support is called an L Bracket and is secured to the outer sill using two type A screws. The frame guides on the underside of the air conditioner line up to fit into the sill bracket to secure the air conditioner.