FC 5-421D 18" Pad Driver Assembly for Factory Cat Tomcat 38, 40, 40HD, 3700 Disc Brush Model Scrubbers, 6 Point Drive Plate. An 18" diameter molded plastic brush block with 1/2" short trimmed polypropylene. The short trim poly digs into and holds your floor pad securely to the brush block with the aid of a pad centering device or "pad grabber". This two piece pad grabber is included with the assembly. 18" diameter plastic block with an 6-point clutch plate (Please check your model for the proper number of points. We offer a 6 point and 8 point clutch plate. Use 19-421D for 8 pt.). Designed to hold your 18" or 19" diameter floor pads. Fits Factory Cat Model 38, 40, 40HD and Tomcat 3700 disc brush model floor scrubbers. Some of these models may take cylinder brushes instead of disc brushes. Please check your model before ordering. Two pad drivers are required per unit. Priced Each. Replaces Factory Cat Tomcat 5-421D. Our Part Number FC 5-421D