Rises your grooming table like Dede does in 90% of her YouTube Videos.  She is 5' 4" and she thinks having the table right at your waist it the best for your back.  She is not a Doctor.  All Sales Final.  Two different height options.  
5'6" or taller need TALL ones (when raising the table with a heavy dog on it higher, if the pet is wild, put the table against the wall for better stabilization.  A second grooming arm might be helpful to turn the dog from one side of the table to the other.  Food for thought.
5'5" regular
5'4" regular
5'3" regular
5'2" don't need any in my opinion