King & Loops 3/8" Stainless Steel Low Port Correction 4" Cheeks The 3/8 bars add a little "bite". The three-piece action breaks over the bars at an angle contacting new nerves. Then the low port as it rotates gives the horse some tongue relief along with the feel of this rotation. This combination makes this a unique mouthpiece with a lot of control and "feel". Port height is 1 1/2" "Lifetime Guarantee"