after going through two of the expensive brands i got tired of spending a lot so i found this brand on amazon. i have been using it for the last year and have been equally as happy with it as with the big name brands. the price is really hard to beat and it does everything i need.
Also be careful with shock training your dog. do a little research before jumping right in. some dogs are a lot more timid than others so id definitely start out going easy on yours.