I have one, but don't know if it is what you would call heavy duty. I would need it back, in case I need another knee replacement down the road.
They are not costly, though, and I live in Jamao, about 1 1/2 hours away from Santiago on the bad mountain road. Don't know if it is worth the drive.
I would check out the price of purchasing one, and if you don't find it too costly, then when you are finished with it, why not donate it to a hospital? Then you would feel good about the expense, because it continues to help others.
And if you don't know where to donate it, you can donate it to Strength for the Journey and we will give it a new home.
But again, you may borrow mine, if you feel it is worth the travel.