The Cosmic Explorer (600-2409) Batteries Faxback Doc. # 33041 Power Base: Is this part of your Cosmic Explorer contains the battery compartment for 4 "AA" Alkaline batteries (not included), such as Radio Shack Cat. No. 23-552, the Power Light, on-off switch and the electrical wiring. Position the batteries as indicated by the diagram molded into the battery compartment. Use the black nylon ribbon to eject the batteries at time of replacement. Should the bulb need replacement, start by unscrewing the three Phillips screws. Carefully remove the bottom of the Power Base by lifting gently. The bulb is held in place by a spring loaded mechanism. Replace the bulb, being sure that the contact rim surrounding the bulb is slid under the spring clip to insure proper contact. Align the base components so the power switch passes through its opening when the two components are assembled. Replace the Phillips screws but don't over tighten. Always check to see that your batteries are properly positioned and fresh. The bulb is a PR 15 or its equivalent such as Radio Shack Cat. No. 272-1125. (BR/EB 5/10/96)