These C9 bulbs have a C9/intermediate/E17 base. [Size Guide]
Used with our C9 Cords or Commercial C9 Cords, they are a 7 watt bulb, are 2" high and 1" wide, and have an average life of 3,000 hours.[Size Guide]
The C9 replacement bulb size is often referred to as Christmas bulbs -- the perfect bulb for the vintage Christmas tree look.