We are on a six month schedule. The shipment comes with the filters and a new battery. The battery is very accessible (unlike the filter system we used previously) and the filters are very easy to install. No need to turn the water supply off (unlike previous system). The only negative is the water flow is pretty low (it takes about 10 seconds to fill an 8 oz glass of water). That's understandable since it is going through three filters but that was pretty disappointing. We've gotten used to it and the water quality is worth the delay.