Base: G23 (2-pin). Bulb for Sunterra Pond BioFilter 300207 G23 Base - 9 w Watts. Ultraviolet for Air. G23/Base - Germicidal Ultraviolet. Clear Stream 1200 Filter UV. LSE Lighting® Extended LIFE 9W 9 watt UV Bulb for TetraPond GreenFree Sterilizer.
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