In an official polo game, every horse must necessarily have a fixed martingale on, for safety reasons. Though, it is better to use every time you play, even for a small stick & ball.
As usual in Polo, the Equipment of the Polo pony is entirely thought to protect the horse and the player from any injury. It is very important to keep the Polo equipment in the best possible shape because any equipment breaking
HELMET: Hard surface internally padded to protect players head. The external surface is covered in fabric or leather; thus the polo helmet is completely customizable. I can have 2 or 4 attachment points for the under-chin band.