A1 Falconry u.k telemetry system..Tested at 15 miles line of sight, 418mhz this is a "low" cost system, paid £295, played with and used once on a M.H.H that was blown a fair way off course in a gale , will not get you to the actual branch your bird is sitting on, but will get you closer to her than none at all !! at the moment will need a 3v lithium battery for the tail mount ( searching the house as I,m sure there is a pack somewhere!)... this system is as new, bought this mainly for ease of mind when money was tight, full instructions included.... £190 contact Paul Dickie..Work phone 07736118201....