The Hitachi HL-6312G is a index guided laser diode with multi-quantum well structure. It has a built in photo diode for monitoring the laser output for use in automatic power control (APC) circuits. The common case pin is laser diode anode and photo diode cathode.
Output Power: 5.0 mW typical, 6.0 mW maximum
Wavelength: 635 nm typical, 640 nm maximum, RED
Operating Voltage: 2.6 Volts typical
Threshold Current: 20 mA typical
Operating Current: 55 mA typical
Monitor Current: 0.4 mA typical
Operating Temperature: -10 to 50 deg.C
Package: TO-9, 9 mm diameter base
A factory spec sheet can be found HERE
Note: Due to the sensitive nature of laser diodes, there is no warranty or exchanges on these items.