NSS 28-9-721-1 17" Poly Back Tufted Pad Driver for NSS 1708 Series Floor Scrubbers. Short trim polypropylene filaments work in conjunction with the supplied pad centering device to hold your floor pad securely. 17" diameter heavy duty molded plastic block includes spin-on brush drive clutch plate (28-9-010-1). Fits NSS Wrangler 1708 series walk behind floor scrubbers. One 17" diameter pad driver required. Priced Each. These are bundled together to reduce freight when two are ordered. Replaces NSS 28-9-721-1, 2897211. Our Part Number NSS 2897211, 28-9-721-1