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
![Amazon.com: Dogtra Edge RT Long Range High-Output 1-Mile Waterproof 3-Dog Expandable Remote Dog Training E-Collar with Combination Boost Control for Professionals : Pet Supplies Amazon.com: Dogtra Edge RT Long Range High-Output 1-Mile Waterproof 3-Dog Expandable Remote Dog Training E-Collar with Combination Boost Control for Professionals : Pet Supplies](https://m.media-amazon.com/images/I/41qX3AuQRgL._AC_UF1000,1000_QL80_.jpg)
Amazon.com: Dogtra Edge RT Long Range High-Output 1-Mile Waterproof 3-Dog Expandable Remote Dog Training E-Collar with Combination Boost Control for Professionals : Pet Supplies
![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 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](https://m.media-amazon.com/images/I/41MRkxJoKxL._AC_UF1000,1000_QL80_.jpg)
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
![Dogtra ARC HANDSFREE PLUS Boost & Lock Remote Dog Training Remote Collar System 644622020826 | eBay Dogtra ARC HANDSFREE PLUS Boost & Lock Remote Dog Training Remote Collar System 644622020826 | eBay](https://i.ebayimg.com/images/g/ZxwAAOSwwBNkCfn7/s-l1200.webp)