It consists of a high quality hard seal 6 inch Siemens or JDS Uniphase HeNe laser tube producing between 0.5 and 1.2 mW and a partially potted Spectra-Physics power supply. The tube has normal metal mirror mounts and anode-end output.
The power supply is a strange shape, a tapered flattened cylinder, mostly copper foil covered, but with some of the low voltage circuitry exposed. The output is set at 3 mA for the Spectra-Physics 007 4-3/4 inch tube. The input connections are via a 7 pin header with pin 1 on the right facing the unit:
There are several ways to control the power supply:
CAUTION: The resistor between pin 2 and +6 VDC is required to prevent smoke. Do not omit!
I haven't confirmed it but believe pins 2 and 3 are compatible with TTL levels. The 1K ohm resistor will still be required for the signal driving pin 2. Pullups may also be needed to achieve high enough HIGHs.
(Photo shorws a 5 inch tube with cathode-end output, but these are no longer available. You will receive a higher power 6 inch tube with anode-end output.)
The anode connects to the foil-wrapped fat yellow wire which exits from the potted unit and includes the required 100K ohm ballast resistor. The cathode connection is via a black wire which also exits from the potted unit. Clips will be provided.
The extra connectors and wiring may be included (not all of these came with everything), though there is no need to retain most of it. There may also be a pushbutton switch that was used to turn the laser on and off (on when pushed).
You will need a 6 VDC power supply capable of 1 A. 4 D cells should work fine.
Although the power supply as shipped may be quite ugly, removing the copper foil and extra wires can turn it into a very cute and compact rig as shown below.