Astro Pneumatic ONYX Flex Head Reversible HD Cut-Off Tool 408 The Astro Pneumatic ONYX Flex Head Reversible HD Cut-Off Tool 408 has a flex-head design allows for setting the tool 25 Degree forward or backward for clearance and a forward and reverse dial, that you choose where the sparks are thrown. Astro Pneumatic ONYX Flex Head Reversible HD Cut-Off Tool 408 features a 0.8 horsepower motor, designed for full throttle heavy-duty applications.