https://www.youtube.com/watch?v=cMlgSNQFAqs

And an e.collar.......

It actually could just be a vibration collar. There is a big difference. A vibration collar for a deaf dog can teach it to look at you. Vibration, treat. Puppies do tend to get sidetracked and with no hearing this can bring the attention back to you.

> A vibration collar for a deaf dog can teach it to look at you

Yes - a neighbour used one for a deaf dog. She could let it off lead and then alert it to her giving a recall signal.

And an e.collar.......

E-collars have been in use in UK as an attention mechanism for around a decade, as you know nothing at all about e-collars thats why you 'appear'
to be surprised.
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It actually could just be a vibration collar.

Some of the Dogtra e-collars have had a vibration facility for at least a decade.

The only manufacturers who made a vib only collar were 'Unleashed Technologies' I was asked to test one here appx 2006 by a UK retailer - I still have it somewhere, anyone want it Ill give a price.
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