Bevel bits are a popular choice in UK show rings. They feature a very mild lever action that causes the cheeks to tilt forward and the mouthpiece to lift up. 
This bit is very effective for ponies and horses who poke their noses or are strung out. It promotes outline and is the next step up from a snaffle. 

This model features a "lozenge" shaped joint that sits flat on the tongue. 

Mouth Thickness: 16mm 
Ring Size: 55mm