Hello Lou, The dog type are what we call Pig Tail Screws and they are
really only useful in really soft loamy ground where they will almost
push in, no good anywhere else especially hard ground. Also they are
made from cheaper steel product that is easy to make but also easy to
bend, ever seen a big dog pulling on one ??

There are a number of tie down systems out there from bits of steel bar
to exotic and sometimes complex devices like the claw, they all have
their fans and particular uses but with a lot of years flying and using
several different types i have found Screw It's to be really good, and
thats why we are selling them. Thanks Michael

Lou wrote:
I've always been curious, what makes these better than just going to
the pet store and buying the dog tieouts that do
the same thing. I'm sure these get a good workout being jerked an
pulled by the big dogs.
Lou