Pond Linear UV Bulb - Pisces 11 Watt UV Bulb 4 Pin Style, a glass tube with 4 pins on one ceramic end. Will Fit Laguna Pressure Flo Filter PF2500 and PF5000. The 11 Watt 4 pin UV lamp fits the Laguna Pressure Flo Filter PF2500 and PF5000.
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