Kamasa spline insert bits for use with a standard 10mm hex  bit holder,with generous multi-buy discounts, following sizes available,we have run out of some sizes now as this line is discontinued

M5 M6 M8 M10 M12

in either 30 or 75mm long

the shank is 10mm hex which is the standard for mechanics bit sets,and will fit in either a 3/8 or 1/2 inch drive holder,both of which we stock.

Please note the picure shows a variety of sizes and holder for example only