APPLICABLE FOR MOST BOTTLES: The plant watering device can be applicable for many size of bottles with mouth opening 0.8in to 1.1in, that's to say, you can use most of drink bottes you drinked before as the water container. You can easily find the bottles in daily life. ADJUSTABLE WATER FLOW : The plant watering Devices design with water control valve which can control the water flow according to your real needs. Please slowly turn the control valve when you need to adjust the water flow. To left is faster and to right is slower. STABLE AIR PRESSURE: The bottle holder provides the water with the stable air pressure, which means the water can drop down constantly until it run out. Unlike other plant watering spikes, they don't design with bottle holder, so they need to drill a hole on the bottom of the bottle to keep the air pressure stable. EASY TO ENSTALL AND USE: Just twist the bottle holder and control valve to the water dripper, then insert the watering spike into the bottle mouth and upside down the bottle and the plant waterer, after what you can insert the watering spike into the soil. ENJOY YOUR VACATION: With the plant self watering device, you don't need to worry about nobody taking care of your plant when you go out for travel on vacation. The plant waterer will take good care of your plant and your plant will grow healthy. Specification: Material: high-quality plastic Color:blue/green/orange Size: 14.5 x 5.5cm Weight: 23g/each Package Includes: 12 x Plant Self-Watering Devices (4 x orange, 4 x blue, 4 x Green) 12 x regulating valves 12 x bottle holder How to Use: 1.Twist the bottle holder to the watering spike; 2. Twist the regulating valve to the watering spike; 3.Insert the water spike into the bottle; 4. Upside down the bottle and insert the watering spike into the soil; 5. Please keep the bottle upright and vertical.