We picked up a set of Tridekon's from DeerStar in Stettler (the JD sprayer dealer network, they have about 19 dealers in AB). They were $5700 for four, to go on our 4720. They have a year warrenty. Tridekon is located in Neepawa, Manitoba. They have ads in "The Book," have seen them at trade shows and they have a dealer network as well.