Everyday use and peace-of-mind battery backup in an aquarium air pump. Penn Plax’s Air-Pod uses 4 “D” batteries for automatic use when the power goes out. Adjustable flow control dial manages dual outlets. Also includes a power indicator light. Air-Pod Battery Back-UpAir Pump by PennPlax.Everyday use and peace-of-mind battery backup in an aquarium air pump. Penn Plax’s Air-Pod uses 4 “D” batteries for automatic use when the power goes out. Adjustable flow control dial manages dual outlets. Also includes a power indicator light. Battery power lasts up to 150 hours. For tanks up to 55 gallonsProduct code: 1931Item No. AE-PP-APB1