Battery operated.  Includes water tank.  This compact system is ideal for watering house plants when you are away on holiday.  No taps or electrical connections are needed as runs on a single 9V battery.  The Oasis system can hold 25 litees of water and will provide irrigation for up to 20 pots.  4 separate programmes (10-20-30-40 days).  The kit comes complete with 10m PVC hose, 20 drippers and 20 stakes