The largest Mochton Stylus "Shark" Concrete Engraver has 64 heat treated impactor teeth that strike the concrete more than 2000 times per minute. Thousands of tiny bites quickly eat into the concrete surface leaving a detailed cut. The operator controls the overall depth of cut (1/32" up to 1/4" deep) merely by moving the Shark's impactors over the surface. A convenient adjustable flow air nozzle is aimed at the teeth to gently blow cuttings away. Precision made of billet aluminum, hardened tool steel and nickel plated steel. Compressor required to power the Shark (8 CFM at 90 PSI).