Set of ten 15mm square by 2.5mm thick by 30 degree

cutter heads with screw.

Four cutting edges, suits most (possibly all)

spiral block cutter heads for planers and thicknessers

15mm by 15mm R150 cutters are sold without screws

these have a slight radius and some people prefer them.

Also available, single cutters (with screw)

and T15 wrench key