Check the listing for details. Blue Heron Stop Koi Protector VED100. Condition: New. Listed at 49.88 USD. Heron Stop from United Aquatics A simple and nearly invisible deterrent helping to protect pond fish from herons and cats. Place the stakes around the pond, 10" - 12" from the pond and about 5' apart, with the stakes pointing in towards the pond. Thread the nylon string through the holes and fasten the bells to the upper string between the stakes. Herons are known to land beside people's ponds. By installing a deterrent around the pond, the heron will not be able to get to your precious koi and will move to another target location. Below is a quick look at the product's key features: Very Easy to Install Comes With 25-Meter Nylon Line Plastic Stakes and Small Bells Included Provides Protection for Ponds Up To 12 Meters in Circumference Also Effective at Keeping Cats and Other Predators Out The kit will protect ponds with a circumference up to approx. 30 ft Listing and template services provided by inkFrog