I carry examples of several kinds of boots, but no longer stock them due to the high cost of maintaining an inventory. I can assist you in measuring your horse's hooves so you can purchase boots online or at a local retailer.  

Know that various boots will not work out on every type hoof, and it may take some experimentation to find the right boot for your horse. Hoof boots should be sized immediately after trimming. Designs vary in shape and so one style may fit your horses hoof shape better than another. Sizes are not standard across manufacturers and also do not correspond to metal shoe sizes.

Hoof Boots take much less time to put on than the saddle and other tack and are well worth the extra couple of minutes to use them. If your horse lives on grass or non-rocky paddocks, he will unlikely be able to go trail riding without boots. I use them on my horse and he loves the protection they give him.

Just like when we get new boots, let your horse slowly break in the boots before going out on a long ride.

Foundered horses really benefit from wearing boots for some time each day so they can more comfortably move around their paddock. This movement increases circulation in the hoof and is critical for healing and new growth. Different sole pad configurations are tried until one is selected that seems most comfortable for the horse. 

HOW TO HELP YOUR HORSE TOUGHEN HIS HOOVES:

To toughen up a barefoot horse's hooves, create a living environment that reflects the kind of ground you wish to ride on. In addition, natural lifestyle will benefit your horse overall...

-A free, small herd lifestyle for psychological and physical well-being.

-Natural track containing dirt, pea gravel, river rock, buried salt and minerals, a hoof soaking pool, and 24/7 access to full stalls for shelter.

-Safe and secure fencing. No barbed wire or mesh fencing.  

-Generously fed grass hay for a low sugar/starch placed throughout the track promoting natural grazing movement.