The AP twin BT is a counter top purifier which connects to a kitchen tap.Comes with adapters to suit 99% on all tap types,has reinforced housings, brass chrome connecters ,spout, lever type diverter and quality doulton ceramic filter plus 1 micron sediment filter.Ideal for tank water, or can be used on town water with a 0.5 carbon filter and sediment filter in areas where high sediment is a problem.