This is a great product.  I used the 3 aspect and 2 aspect signal heads for modeling a C&O cantilever signal and a mast signal.   I normally model the N&W but wanted an interchange with the C&O—hence the need for the iconic C&O signals.  In addition to the head, photo etched details (#1) were the perfect companion to complete the build.  #603 red/yellow/green LEDS were used.  These are extremely small LEDs that fit nicely into the signal heads.  I used some Northwest Shortline motor mount compound to hold the LEDs in place until the back plate was installed.  Alternatively any soft material such a silly putty should also work—you just need something the hold the LED in place until the back plate is installed.  For lights, I used an LM2596 circuit (Amazon) that allows adjusting the voltage to obtain the desired brightness (adjustable down to about 1.25 Vdc). Interesting the 3 LEDS (red/yellow/green) all took different voltages to obtain the same brightness.  To avoid using 3 separate LM2596 circuits, I installed a 2.4K ohm resistor in series for the red LED and a 1K resistor in series for the yellow resistor.  The green LED required no resistor and as such, the LM2596 output was adjusted to obtain the desired brightness.  The resistors on the yellow and red LEDs then were sized to obtain the same brightness as the green.  The LEDs do need to be handled very carefully since the thin wire can be easily snagged or broken.  Work slowly, carefully and patiently and all should be fine.  A standard soldering gun will provide enough heat to burn the lacquer insulation off the wire—-no need to sand the wire.  In summary, the various Showcase MIniatures products contributed greatly to make a very nice set of C&O signals. 

Looks good and has very little flash clean up.

Love the quality