Heller trijet sds plus hammer bits heller 27224 7 these 8 x 110 x 50mm trijet sds plus hammer bits from heller are 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 in packs of 10 heller 27224 7 2618 trijet sds plus hammer bits 8 x 110 x 50mm pack of 10