Built in England on a Frank Baines tree this saddle is in excellent condition and features supple leather and a padded seat, making it very comfortable. Balance International Saddles are designed to sit a couple finger widths behind the edge of the scapula. They have a wide gullet, which when used in conjunction with pads that include shims. Provide a custom fit for the horse and allow freedom for the scapula to move. This is an older model with only the tree size stamped on the inner flap. The seat is likely a’C’, which is 17″-17.5″ The following information is from the Balance International website: GPD stands for General Purpose/Dressage. This style works very well for riders who want to focus on flat-work and dressage, but also include some trail riding and small jumps into their horse’s programme. It is also loved by many riders who compete in Dressage to a high level. It is very useful for riders who are long in the legs between the hip and knee and find most dressage saddles are too straight in the flaps for them to be comfortable. It is also the most popular style for : -Endurance & Long Distance -Showing. Let me know if you have any questions.