PetSafe "static" remote training

[PMJ]

Thinking about purchasing one of these for our dog. She's a lab-mix about 40 lbs. Planning on using it when she is in the backyard, trying to jump the fence or just barking excessively (all of which she does too much). Should I get the one for "big dogs" or "little dogs"?

I'm even thinking if it works, I could use it to take her on walks w/us and I could actually manage her and DD.

I have read many reviews and it seems like they are not harmful to pets.

Your thoughts if you have the product?

thanks!