This device uses tight tolerance guide holes to position fibers for cutting with standard blades (included). Jacketed and unjacketed fibers may be cleaved with this instrument: from 750 to 3000 micron unjacketed, 750 to 1500 micron jacketed (includes duplex fibers), and all 265 micron fiber bundles. Holes accept 750 to 3300 micron outer diameters. 90° ±0.2° Cutting Angle. Cutting block included with Optical Fiber Hot Knife #54-014.