> Our club is assembling items to fly on a balloon in the near future and I know that not all GPS models work properly above 60,000 feet. Where can I find out which ones will be suitable? Argent Data also have one here https://www.argentdata.com/catalog/product_info.php?cPath=23&products_id=144 Rated >25km -- Rob, VK6UFO, VK6RN