UA-STP-BP 24"x 16.5" Class A Rectanglar Stepped Shape Diffusor – QTY 4. Ultimate Acoustics UA-STP-BP Stepped Diffusors combine shape and a hard, high-impact surface to diffuse sound evenly across the room to control “flutter & echo” effects. The UA-STP-BP is a great choice for tracking spaces, control rooms or any environment in need of controlling sound reflections. The Class A Stepped Diffusors help maintain a “live” sound and lend a sense of dimension to any room. The UA-STP-BP comes in a black textured finish.SpecsSize: 24" x 16.5"Type: Class A DiffusorQTY: 4Design Style: Rectangle/SteppedColor: Black.