10mm tappet adjusting nut. Sold individually. Fits VW T2 Bays with 1800, 2000cc Type 4 engines from 1974 to 1979. Also fits VW T25s with 2000cc aircooled engines from 1979 to 1983, 1900 watercooled engines from 1989 to 1992, and 2100cc watercooled engines from 1985 to 1992.