The WS7-IR-ll wavelength meter manufactured by HighFinesse GmbH measures continuous-wave and pulsed lasers up to 2250 nm with a relative accuracy of 10–7 and an absolute accuracy of ∼50 MHz or 0.1 pm at 1064 nm. Based on a Fizeau interferometer, it has no movable internal mechanics or optics and operates at a speed of up to 500 Hz. The multichannel option enables measurement of up to eight lasers at a time. Active control of the lasers is provided by the PID controller, and the meter connects to a computer via a high-speed USB 2.0 interface. Software is included.