The Norman Lamps 428 is a G4½ krypton gas filled miniature bulb designed for indicator, instrument panel, and low-voltage specialty lighting applications. It operates at 12.50V with a draw of 0.25A, producing 3.125 watts of power and a light output of 3.5 MSCP (Mean Spherical Candlepower). The krypton gas fill is a key feature of this miniature incandescent bulb, enabling a significantly extended average life of 1,000 hours compared to standard air-filled equivalents of the same ANSI designation, while also delivering brighter output relative to consumed power.

The bulb features a G4½ globe envelope measuring 1.06 inches in length and 0.588 inches in diameter, making it a compact fit for tight sockets and enclosed fixtures. It uses an E10 miniature screw base for easy, secure installation in compatible sockets. The CC-2V coiled-coil filament design contributes to consistent, uniform light distribution across a full 360-degree viewing angle, characteristic of globe-type miniature incandescent bulbs. The color temperature of approximately 3850K produces a crisp, bright white light with a warm character suitable for visibility-critical indicator and display applications.

Rated at 12.50V, this krypton miniature bulb is well suited for use in low-voltage instrument panels, signal indicators, specialty lighting fixtures, and equipment requiring a precise voltage match. The E10 miniature screw base is a widely used standard in low-voltage miniature lamp sockets, making the 428 a reliable replacement or retrofit choice. This bulb is sold individually and is also available by the case in quantities of 10.

• Krypton gas filled G4½ miniature incandescent bulb rated 12.50V, 0.25A, 3.125W with 3.5 MSCP light output
• Extended 1,000-hour average life — significantly longer than standard air-filled #428 equivalents — thanks to krypton gas fill
• E10 miniature screw base and compact globe envelope (1.06 in. L x 0.588 in. D) for easy installation in low-voltage sockets
• CC-2V coiled-coil filament delivers full 360-degree light distribution at approximately 3850K color temperature
• Dimmable design compatible with variable voltage control circuits; voltage rating must match application exactly for correct brightness and life
• Sold individually; order 10 for a full case — ideal for indicator panels, instrument lighting, and specialty low-voltage fixtures