It can be used with a discarded beverage bottles, mineral water bottles.<br />  Different water bottles have different calibers, please select the appropriate bottle. Coca-Cola bottles can be used.<br />  Please note that seepage water will fast if the head is not plugged in the soil,but in the soil it will be slower.<br /> <br /> Specification:<br /><br /> Material: PP<br /><br /> Size: 3 x 13.5cm<br /> Bottle neck diameter application: 3cm <br /><br /> Weight: 20g<br /><br /> Color: Green, Blue (Random)<br /><br />  <br /><br /> Package includes:<br /><br /> 1 X  Automatic irrigation controller