The Medium Ring Gag is stronger than the usual Loose Ring and Eggbutt as the ropes going through the rings create leverage which will exert more pressure through the mouthpiece whilst at the same time introducing more poll pressure.
The Barrie Reversible is a severe bit due to the center links of the two pieces being offset by 20 mm giving it a double nutcracker action, which creates more tongue and bar pressure.
It is a versatile bit that can be flipped and used either way. The Round Twist providing a harder bit and the Smooth creating a more forgiving and softer bit.
Great bit for the experienced rider and strong older horses.