You can select wavelength among 1309nm, 1474nm, and 1556nm at the front panel of the instrument. Optionally you can change from laser to LED with low power adn wide spectral width, by pushing switch at the top middle of front panel. Laser modules are in 14-pin butterfly with TEC (see 9th photo below). There are two 1x2 optical switch (JDS P/N: SN12ADU-FP) inside the instrument to select laser source module. There are two 1x2 3dB couplers (JDS P/N: AC1100-A3-0.6). The 3 laser modules are driven by a regulated linear power supply (GHOF 1-5 Rev.A, output 5V 3.0A). FC/PC adapter at output port. Internal SM fiber connectors of 3 ports look clean under fiber scope for female connector. We tested output power after at least 40 minutes warmup (see 3rd photo below) and optical spectrum (see last 6 photos below. Center wavelength data is from OSA test with RBW=5nm or 10nm, there is no enough warmup for OSA test). Tested laser output power and center wavelength at left optical port of front panel: -27.305dBm 1304.45nm at 1309nm port, power stability is very good. -9.081dBm 1473.88nm at 1474nm port, power stability is very good. -9.598dBm 1555nm at 1556nm port, power stability is very good. Output power of the middle port and right port is 3dB lower than left port. Original tested optical spectrum result by JDS was labeled on 3rd photo below. AC input: 110V/120V is standard option. Upon your request, we can change to other AC input voltage option by re-wiring inside instrument. A power cord will be attached. Net weight: 4.4kg. Dimension: 30x28x14 cm