Hi there Just a followup review for any people that may be considering the invisible fencing as an option. We are on a 3 acre block and installed the invisible fencing for our 6 month rottie, who is now over a year old. Have not had any escapes, and to this day still refuses to get close to the flagged zone. The 3-4 weeks training was a small price to pay, as we decided to extend the fencing so had to retrain for that exclusion zone too. Highly recommend this product and as long as you are willing to put in the effort for correct training you can't go wrong!!!!