Argon/krypton lasers that produce a variety of wavelengths at low- to mid-range outputs have been released by Lasos Lasertechnik GmbH. The LGK 7990 and 7991 incorporate internal mirror tube technology to provide permanent beam alignment and to eliminate contamination. The company says the lasers offer improved thermal stability, longer lifetimes, and low electronic and optical noise for use in applications such as laser scanning microscopy and bioanalytics. Both models operate between 568 and 488 nm, have beam quality M2 of 1.2 and polarization of >100:1, and produce <2.0% rms noise from 20 Hz to 2 MHz. Output power of the LGK 7990 and the 7991 is 5 mW/5 mW and 10 mW/10 mW, respectively.