Unique balloon with knobs provides unsurpassed stability for effective & safe dilatation in all situations where it is desired to avoid balloon slippage. Slippage of a balloon during inflation may cause unintentional dilatation and damage by the dynamic impact of the slipping balloon, causing trauma up to vessel rupture. Optimal for dilatation of in-stent restenosis, short very calcified lesions, in delicate areas such as bifurcations.