Durock Foam Switch Films make mechanical keyboard switches more stable by reducing wobble between the top and bottom housing. The soft foam material compresses between the top and bottom housing to help dampen noise producing a perceptually lower pitch.
Specifications:
Great for older switches or switches with looser housing tolerances. Might be me being crazy, but I feel light it really completes the switch. I have these on my MX Blacks and I feel content. Spiritual experience. 5 stars!