You're not ready to put an electronic dog collar on your pet until you've done two things.
With so many choices, it is easy to find a small dog collar that fits snugly but not too tightly, and is the appropriate width for the dog's size, personality, and coat.
The type of electronic dog collar you choose should be directly related to what you want to train your pet for.
Whether the use of an electronic dog collar is cruel depends on the user.
Total E-Collar Conditioning features trainer Mike Lardy who will help you learn how to properly field train your dog using an electronic dog collar.