This softener is supplied partailly assembled for shipping. Some assembly will be required. All components and instructions will be supplied.
The softener size is the physical size of each of the vessels given in inches (eg 7" x 35").
The figure in litres is the volume of the softener resin for each vessel.
The lph (litres per hour) figure is the maximum flow rate to achieve complete soft water - higher flow rates are possible but the water will retain some residual hardness.
The capacity is the volume of water it can soften before the softener requires regeneration - this figure assumes a hardness of 300 ppm CaCO3 (calcium carbonate). If your water is harder this figure is reduced and if your water is softer then the capacity is increased.