Colour Indicating Deionization
https://www.resin-products.com..../997/colour-indicati
Aries FilterWorks offers colour changing deionization cartridges for easy indication of resin exhaustion without the need for monitors or indicating lights.

Domestic Filtration
https://www.resin-products.com..../cat/118/domestic-fi
Domestic Filtration. Resin Products Limited is a leading supplier of high-quality ion exchange resins, RO membrane systems & products.