When you are jacking up a vehicle with a
hydraulic floor jack, sometimes you have to position the jack in odd
places to get it elevated the way you want it. Sometimes it
might be right on a the u-bolt threads or maybe on a painted surface
that you'd rather not scratch up.
I found that placing a hockey puck on the jack
gave my jack a little grip and a little give. A hockey puck is
made of a very hard rubber material and will give a little, which is
good news for the threads or the painted surface. I just had
to make sure I was lifting on a safe location on the vehicle so that
it wouldn't slip off.