Home / Appliance / Parts / Captive Air Tank Bladder U20-8 Captive Air Tank Bladder U20-8Price Not Available Price may not be up-to-date. Out of Stock View Product Part Number: U20-8 Brand: STA-RITE INDUSTRIES Seller: Sears PartsDirect Categories: Appliance, Parts Possible Matches$139.99Litheli U20 Pole Saw for Tree Trimming, 8'' Electric Cordless Pole ... Description This bladder (part number U20-8) is for captive air tanks. Bladder U20-8 keeps the air and the water separated in the tank. Follow the instructions in the manual when installing this part.