The LBTEK Ultrafast Mirror Kit is sold as a combination of Ultrafast Mirrors and optical mounts. Each kit contains 6 identical Ultrafast Mirrors and 6 AMM-1B mounts. A single purchase provides a complete beam steering unit, eliminating the hassle of separately selecting mounts. Femtosecond laser pulses have extremely short pulse widths and broad spectra. The coating dispersion of ordinary mirrors introduces Group Delay Dispersion (GDD), causing pulse broadening and reduced peak power. By optimizing the Dielectric Coating design, Ultrafast Mirrors keep GDD at an extremely low level while ensuring high Reflectance, making them an essential component for building the optical path of femtosecond laser systems. LBTEK Ultrafast Mirrors are coated with low Group Delay Dispersion Dielectric Coatings on Fused Silica substrates and are used at 45° incidence: s-polarized light has Rs > 99% within the nominal operating band, and p-polarized light has Rp > 99% within the core band; across the full band, |GDDs| and |GDDp| are both < 30 fs², maximizing retention of the time-domain characteristics of femtosecond pulses. The AMM-1B mount in the kit secures Ø25.4 mm Mirrors via M4 nylon-tipped set screws, enabling ±4° pitch/yaw adjustment. Angle fine-tuning is performed via a precision thread pair to meet precise optical path alignment requirements.