I'm assuming we're talking about the same thing...we call them
skid boots around here. A firm boot (without the foot part) that wraps around the stop pad?
These are the ones I used to use for Ripley...I got them from a friend whose dog detested anything on his feet, and wouldn't play with them on. So I inherited them...and used them for Ripley a little big. He would tear up the back of his big main pad while playing flyball...the boots were much easier than vet wrapping every race.
http://webpages.charter.net/dhfm/ZControl.html
They hold up well, unless you
forget to take them off after a flyball run and leave them on a dog who likes to chew things off their feet.
I still have Rip's old pair...I just keep them around in case of accident. They do form to the dog's feet...so I can't use them for any long period of time with the others...but I just keep them in case of injury.
Here is a site for DIY skid boots.
http://www.flyballequip.com/skidbootplans.htm
"I don't have any idea if my dogs respect me or not, but they're greedy and I have their stuff." -- Patty Ruzzo
"Dogs don't want to control people. They want to control their own lives." --John Bradshaw