6V 20Watt Halogen Bulb for use in Chart Projector Models:
 
Reichert 12084 Longlife Projector
Reichert 12030 Selectra Auto Projector
Marco Model CP-670 Auto Projector
Marco Model CP-690 Auto Projector
Marco CP-2 Manual Projector
Nikon Model NP-3 Auto Projector
Nikon Model NP-3S Auto Projector