Cosmos&reg; Plastic Plant Watering Spikes Water Bottles Economical System (Blue&Green) Keep plants watered while you're away from home. Economical garden watering spikes. Fits general plastic water bottles. Each piece about 5.5" length with opening width of 1.1" diameter. Spikes come without holes, please drill holes with a nail according to your custom need of water flow rate. Hard plastic material. Each pack with 8 pcs watering spikes.