The Har-Tru 4 Ft Tow Scarifier is a heavy duty tool for loosening court surfaces. This model has two rows of case-hardened nails and is heavy enough to allow the nails to really penetrate the surface. Especially good for sunbaked Southern courts that have excess calcium buildup. Truly a workhorse for reconditioning clay courts. The scarifier can recondition compacted clay courts with its two rows of case-hardened nails to penetrate the surface. The nails are staggered on each row to prevent clumps, and sized to fit between the alley tapes.Features:4’ Wide, 2 Rows of Nails, 61 Nail Per RowSized to fit between the alley tapeLevered wheels lift unit over tapes so tapes can be left in placeAdjustable tow hitch fits most utility vehiclesAdjustable steel rails lower nails as they wear downRemovable steel plate allows for easy nail replacement40D nails: 3/16" diameter by 5" longThe Har-Tru 4 Ft Tow Scarifier is especially good for for loosening court surfaces on sunbaked Southern courts that have excess calcium buildup.