HA7037 Tomato & Vegetable Dripper Pack HA7038 Tomato & Vegetable Dripper on Spike Pack. The All-Terrain TOMATO PC Drippers are ideal to water tomato seedlings & vegetables. They provide responsible amounts of water to be used without over watering. Each dripper emits up to it's pre-set 4 litres per hour. Giving great water savings for the garden. It's never been easier to set up a vegetable garden irrigaton system! What is Pressure Compensating (PC)? Pressure Compensating, commonly known as "PC", is a technique that provides a constant pre-set drip rate to watering systems. Regardless of varying water pressure, slope of the landscape, distance from the tap/water source or height of drippers on the same mainline. PC ensures all the drippers perform equally. Suitable for long distances: The primary purpose of PC drippers is to have equal performance, for all drippers that operate on or from the same mainline. Previously drippers close to the water source perform better whilst drippers at the end of the line emit less or no water. PC helps retain a consistent flow of water coming through each dripper and assures regularity even over sloping surfaces. Applications: The 4mm inlet barb allows two types of installation. Firstly they can be pushed straight into the 13mm or 19mm main water supply line. Often used through vegetable beds. Secondly & more commonly, a length of 4mm flex tube is used to connect the dripper back to the supply line and is ideally suited to potted tomato's or herbs. Suitable for All-Terrain applications: The best thing about PC drippers is that they operate evenly on all terrains. It simply takes out the guess work when setting up or modifying an existing system and allows the focus come back to water saving and supplying the right amount of water to each plant or vegetable. Blockage free: Each PC dripper includes a rubber diaphragm. This stops insects entering the pipe & internally, the diaphragm eliminates debris entering the small water path. This rubber diaphragm prevents the drawing in action of material that can occur, through the vacuum like action that can take place. The diaphragm assures smooth water flow throughout the poly pipe so that it can remain free from blockage. Self Flushing: Unlike your ordinary drippers that require frequent flushing, the ALL-Terrain Drippers are self flushing and each time the dripper is used, water flushes through the dripper before the diaphragm is into position allowing the dripper to flush clean every time it is used. Water Saving: The regulated discharge of water through a PC dripper allows you to water your garden the 'Smart & economical' way. Now that's smart watering!