This bit is designed with small rings that are more suitable for smaller heads. The curved mouthpiece provides space for horses with larger tongues and is 12mm thick with a 50mm cheek height. The available sizes are 3" (7.5cm), 3.5" (9cm), 4" (10cm), 4.25" (10.5cm), 4.5" (11.5cm), 4.75" (12cm), 5" (12.5cm), 5.25" (13cm), 5.5" (14cm), 5.75" (14.5cm), and 6" (15cm).