Honda Insight Tail Light Bulb Size

Additional Notes

• The Honda Insight uses two distinct tail light bulb types across its model years: the 7440NA for 2021-2022 and the 7443 for 2000-2006.
• Both the 7440NA and 7443 are ANSI-standardized T20 wedge bulbs rated at 12 volts, sharing the same physical form factor and base voltage.
• The 7443 is a dual-filament bulb rated at 21W and 5W, meaning it supports two independent brightness levels within a single housing, a configuration commonly used where one circuit handles running light duty and another handles braking or signaling functions.
• The 7440NA is a single-filament bulb rated at 21W, incorporating natural amber-tinted glass that produces a warm amber output without requiring an external amber lens or colored coating.
• Although both bulb types share the T20 wedge form factor, the 7443 carries a dual-filament design while the 7440NA is single-filament, making them functionally non-interchangeable despite their physical similarities.
• The natural amber designation in the 7440NA refers to the glass envelope color, which filters the light output to an amber hue at the source rather than relying on the vehicle's lens to produce that color.
• The wattage difference between the two types reflects their filament configurations: the 7443 draws either 21W or 5W depending on which filament is active, while the 7440NA operates at a fixed 21W through its single filament.