Avocet Sports Technology, based in The lawsuit, filed in the U.S. District Court of Northern California, also claims Amer is still infringing on its patents “by introducing, demonstrating, using, making, marketing and selling altimeter devices, which embody the patented inventions.” The suit seeks Amer to render an accounting of all profits it has received by infringing on the patents as well as treble damages and attorney costs. Avocet also does business under the name, Vertical Instruments.