The Sylvania 54248 lamp has a T3.5 bulb shape and a GY6.35 base type. It operates with 100 watts and 12 volts and will typically last an average of 50 hours. This bulb has a base down/horizontal burning position. The 54258 bulb's corresponding ANSI code is FCR. This lamp has a color temperature of 3250 Kelvin and is typically used in microfilm, microscope, medical and 8mm movie projectors.