Outdoor Window AC Covers by ALPINE HARDWARE - Air Conditioner Protection Cover BLACK, 15" x 21" x 16") These are a Square T-Knob

These are a Square T-Knob

-Reduces heating costs in the winter significantly

1-3/8" Projection (from mounting surface to top of pull)

-Protects the inside of the air conditioner from debris

Outdoor Window AC Covers by ALPINE HARDWARE - Air Conditioner Protection Cover BLACK, 15" x 21" x 16") These are a Square T-KnobAlpine Hardware offers an outdoor window air conditioner cover. Construction: Alpine Hardware's outdoor window ac cover is made of a black 600D polyester that fits tight and snug all the way to the back of your window ac unit to prevent drafts. Features: Reduces heating costs in the winter significantly. Protects the outside of the air conditioner from debris. Resitent to winds, rain, and snow and makes sure the elements don't ruin your window air