Dogtra - The Dogtra Combo has 8 stimulation levels and is paired with the Combination Boost Control system that gives 3 levels of instant boost per stimulation level. The front facing Selector
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Dogtra 3502X Long Range IPX9K Waterproof 1.5-Mile 2-Dog Expandable DUAL DIAL Remote Dog Training E-Collar for Professionals Competition and Working Dog Trainers : Amazon.co.uk: Pet Supplies
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