Pentair IS4 Spa Side Remote, 4-Button, Black, 50' Cable | 521891 Throw Pillow Includes 3-9-459 as the SKU

Includes 3-9-459 as the SKU for quick procurement reference

Hayward manufactures cartridge filtration systems widely installed in residential pools

It appears in pump and filter assemblies as a connection point at the wall interface

In most installations

Inspect surrounding seals and hardware during installation

Pentair IS4 Spa Side Remote, 4-Button, Black, 50' Cable | 521891 Throw Pillow Includes 3-9-459 as the SKUWhat This Part Is Used For Pentair 521891 IS4 Remote 4 Button, Black, 50ft is a wired remote used with compatible Pentair automation systems. It allows control of selected pool functions from a secondary location. Why This Part Matters A dedicated remote adds convenience for spa or poolside operation. Replacing a nonresponsive unit restores direct control without accessing the main panel. Proper wiring length ensures flexible installation. Key