This device turns most plastic bottles into a watering reservoir - perfect for when you are away from your beloved plants. The irrigation kit is gravity fed - it lets water flow out of the base using a tap system - unscrew the easy-to-use tap to achieve the required flow rate of water - the air is let in through a hole punched in top of the bottle. Now you can leave your plants, safe in the knowledge they'll be automatically watered correctly. Easy to use, the kit comes in a pack of 16 with full instructions. The cap measures 28mm across, so fits all bottles with a 25mm neck diameter – make sure to measure your bottle to ensure this dimension is correct. Please note, smaller, 50cl bottles tend to have wider necks that don't fit, while the larger bottles have smaller necks that do fit. * Fits bottles with 25mm neck diameter * Pack includes 16 irrigation spikes * Bottles not included