The SF30 water softener filter set content 4 filters:
2 units PP cotton. 
1 unit Cationic Resin water softener.
1 unit T33 coconut activate carbon.
No RO membrane inside.
The softener should replace the 2nd filter for the Purify guru RO drinking water system.

The SF30 content the premium, industrial grade gel polystyrenic strong acid cation exchange resin supplied in the sodium form. Its principal application in the sodium form is in water softening.

The Resin is a high purity premium grade bead form conventional gel polystyrene sulfonate cation exchange resin designed expressly for the treatment of foodstuffs, beverages, potable waters, and water used in the processing of food.

Its high bead integrity, excellent chemical and physical stability, and very low extractables content play a large part in its successful employment in these areas.

Basic Features:

• Application – Food grade softening – supplied in Na+ form – Potable Use
• Polymer Structure – Gel polystyrene crosslinked with DVB
• Appearance – Amber, clear spherical beads
• Functional Group – Sulfonic acid

Na+ Typical Physical & Chemical Characteristics:
Total Capacity, Na+ Form (min.): 1.9 eq/l (41.5 Kgr/ft3)
Moisture Retention, Na+ Form: 46 – 50%
Particle Size Range: 300 – 1200µm