Aluminium oxide.
For woodworking applications on portable orbital sanders.
Available in either:-
40g, 60g, 80g, 100g, 120g, 150g
Manufacturer codes: WHS40, WHS60, WHS80, WHS100, WHS120, WHS150
Manufacturer codes: WTS40, WTS60, WTS80, WTS100, WTS120, WTS150