Product review (3 stars): Can't,  beat the price! And is a heavy duty.
I though I ordered the the newest  heavy duty coupler the only difference between models is a letter at the end of the model number, but the model without a letter supposed to be better, but I need it right away so I decide to give it a try.for the picture it looked like the newer coupler was made of rubber and nylon and not solid rubber. But so far ok, can't complaint about the price, overall very good buy