Narrow Gauge Wheel Assembly, 3"X 16", with one metal rim, one nylon rim and 40mm double row ball bearing. Fit John Deere Grain Drills 750, 1560, 1590, 1690, 1835, 1850, 1860, 1890, 1895, 1990. 2510H applicator. White 8000 series. Narrower design allows unit to run on cleaner seed bed and allows clearance for trash. Great for narrow row soybean planters. Replace OEM #AA66988, 87673693