Easy to Replace Provides 10,000 Hours of Service This 22 Watt T5 Circular Replacement Bulb is used for all Zadro Magnifying Mirrors With Surround Light. Utilizing simply the best and brightest, low heat fluorescent technology with 100 watt output using only 22 watts of energy. It provides 10,000 hours of use and can be quickly and easily changed. Replacement bulb for Zadro SA , MSA , SW , MSW and SS Series Lighted Makeup Vanity Mirrors Outside diameter: 7-1/4 in (184 mm) Inside diameter: 6 in (152 mm). Note: These T5 22W replacement bulbs are designed specifically to work with Zadro Mirrors. Though size and design may be similar to other T5 22W bulbs, it is not recommended nor guaranteed that these will work with any brand mirrors other than Zadro.