Ps was very lucky to get my bushing dog back this season, took his tek2 collar of him and he bolted one, he followed to ground on a wall with about 20 odd earths all the way accros dead thick cover on it. If my mate wasn't there that day id never got him back, he's a terrier beagle with 1/8 spaniel little to big for most earths but when he does it's no fun. Took us hours to find him and get him back he was wedged in very tight. Very very lucky