Its very dificult for a ring to come off after being caught on something when getting released, when he ETS ring is placed on the bird, there is a double click, that makes sure that the ring is correctly on,some people only click it once. These rings in my opinion, arent easy removed from the birds leg. This is happening to lot to fanciers who fly with ETS,and its a shame that people are stealing from one another for the sake of £1.50