jeross came on the market a number of yrs ago for around the same price and there where terrible,not gps but a tracking system none the less.if you look at the listing there is no info regarding ,distance it can track ,how upto date the info is .i.e if the bird moves, like they do how much behind is it ect,how close the within x amount of meters they say it will be accurate to ,there is alot of factors you need before commiting to this .hopefully the inventor will be back on tonight and answe all these.if the unit does what it says on the tin it must of been on field test with respected faclon