Compatible with the Inductance rectifier lamp (magnetic ballast). This bulb is marked with AN9W/UV

Currently there are 2 type of replacement bulbs available for your lamp. Please include the serial number listed on your bulb, if available, and the ballast type in the comments section during your checkout.

Magnetic Ballast Bulb
Electronic Ballast Bulb

You can determine the type of bulb required for your lamp to perform properly in a number of ways:
Star/eco lamp weighs about 7lbs == magnetic ballast
Star/eco lamp weighs about 4lbs == electronic ballast.

Lamp is more than a year old  == probably magnetic ballast
Lamp is less than a year old  == probably electronic ballast

Please see important information about UV blubs at THIS LINK.