Base, Shape and Dimensions Base: G4 2Pin Bi-Pin with 4mm pin distance Shape: T3 Tubular JC Diameter: 0.375 inches Length: 1.19 inches Please make sure the light bulb base matches what your light fixture has. A common confusion is with G8 2-Pin light bulbs because they look very similar in photos, but the G8 has a wider pin distance of 8mm instead of 4mm. Please verify your pin distance prior to order. Lighting Features Power: 20 Watts Luminous Flux: 280 Lumens Voltage: 12 Volts AC or DC Beam Angle: 360 Degree Material: Glass Color Rendering Index (CRI): 100 for vivid and enhanced color Instant On. No Mercury. : 2,000 hours (1.8 years with average of 3 hours use per day) CE and RoHS certified Working with Halogen Dimmers These halogen light bulbs are dimmable using the dimmers designed for incandescent & halogen light bulbs. All incandescent and halogen light bulbs are dimmable using traditional dimmers, as these dimmers simply adjusts the voltage level for dimming. Dimming using LED only dimmers will result in incompatibility, as LED dimmers work very differently. Please check the compatibility of your dimmer switch or light fixture prior to purchase.