Drip Controller: Water will slowly flow through the device for 15 days, automatically watering your plants. The drip speed is up to you. Easy-to-use flow control ensures your plants are watered at all times. Simply screw the nail into a water bottle full and insert the tip directly into the soil near the stem of the potted plant. You don’t have to worry about watering your plants when you take a short break, this nifty device can simply attach to any screw-top bottle and water yourself. Combine water and plant food in a bottle, then use water nails to deliver the nourishing solution ultimate. Package includes: 12pcs flower nails