Replacement * G23 Bi-Pin Base UV Light Bulb 13W for SunSun JUP-23 Filter ZVQU451 | eBay
Amazon.com: E-Simpo 3pcs B22 E26 E27 to G23 Lamp Base Adapter E27 to G24 Adapter E27 to G23, fit Both 2pin and 4pin Don't fit GX23,NO Ballast Inside. Physically Change Contact (E26/E27