Water Spikes Adjustable Valve - Precision Controller，the sustained release drip last for 1-15 days， prevent over-watered, promote healthier roots and the water spikes will not become blocked by mud. More Compatible - Suit for more beverage bottles. Suit for Dr.Pepper bottle,Pepsi bottle Coca-Cola bottle,Lipton bottle,Diet Coke bottle,Aquafina bottle or other1.1-inch inner diameter bottles. Easy to use - No tools are required for installation,just drill some holes in the bottom of the bottles to keep the air flowing.