ABOISTOP COLLAR REFILL (CITRONELLA) 75ml Available in Citronella, Odourless or Mustard (75ml) Suitable for Aboistop & Masterplus spray collars, & other spray training collars. Easy to use. Long shelf life. The Aboistop dog training collar Kit uses an electronic sensing unit to release a brisk jet of citronella towards the dog's chin when he barks. The combination of smell & noise will distract the dog & stop barking. The Aboistop Kit is used to control problem barking. At each bark, the collar releases a spray of natural citronella oil, that surprises the dog. He will stop the unwanted behaviour & try to locate the source of the strange smell. Gradually he will learn that when he smells the scent, he is forbidden to bark. Aboistop products are humane & harmless, this is NOT an electric shock collar. Aboistop is said to be highly effective & it comes with a two year manufacturer's guarantee.* Helps stop nuisance barking* With electronic sensing unit* Automatically releases spray of citronella* Humane* Harmless* Highly effective* Two year manufacturer's guarantee