Heller trijet sds plus hammer bits heller 26757 1 this 8 x 310 x 250mm trijet sds plus hammer bit from heller is part of a new generation of hammer bits designed to give powerful fast and consistently high performance made from extremely wear resistant tungsten carbide alloy for a long service life supplied singly heller 26757 1 2618 trijet sds plus hammer bit 8 x 310 x 250mm single