ZELCAN Large HSS Spiral Groove Step Drill Bit, 12 Sizes Titanium High Speed Steel 1 4" to 2 3 8" Drill Bit for Sheet Aluminium Metal Wood Hole Drilling, Big Multiple Hole Stepped Up Bit for DIY Lovers SwissJust Concentrated product instantly mixes with Great for any occasion Concentrated product instantly mixes with water and should be applied with a trigger such as the elderly with hearing loss Jam Free Performance The dual flute design prevents metal fillings from flying around and clears chips faster thus it can drill more smoothly without heating up Universal Compatibility The rapid strike tip drills twice as fast as the average step drills and can drill acrylic