The CSR-1575 is designed to slit and ring cables, buffer tubes and jackets on fiber optic cables up to 7.5mm (0.3") in diameter. The tool features an easily adjustable slit blade and ring blade as well as a removable and reversible V block that improves slitting performance and accommodates smaller to larger diameter cables. Simple to use: Ringing a cable: Ring blade is easily adjustable using the adjustment knob. Rotate the knob toward the "+" sign to increase cutting blade depth and rotate the knob toward the "-" sign to decrease cutting depth. Once depth is determined, open jaw, insert cable, rotate tool around cable 3 times, open jaw and remove cable, pull off jacket. Slitting a cable: First select which V groove is needed on the V block, we recommend using the small V groove for cables 3mm or smaller and use the large V groove for cable larger than 3mm. To remove V block simply push on the V block, remove from tool. Select groove then push V block back into tool. Set the depth of the slitting blade by loosening the screw holding the blade in place, use the tab on the blade to move the blade up or down to the desired slitting depth, tighten screw. Open jaw, insert cable to be slit, close jaw and pull. Cut Type Ring, Slit Cable Type Jacket Cable Diameter 1.2-7.5 mm Weight 0.132 lbs (59.87g)