That's an LED. If I didn't have a string of them to look at every time I build another, I would have to go and look it up somewhere else. It is for a 5687 and two would probably be best. The pot for setting the current of the CCS ought to be a 500R or 1k multi-turn unit. Set it for 15 mA per channel. A 9V, some clip leads, and a DMM with current measuring capability is allthat is required for that. rig a single series circuit with the DMM, 9V and CCS, and twist the screw until you get the required current.
regards,
Douglas