This is our most popular Sprenger curb bit (ie-premium). Now, with 12mm thick, slightly slanted and smooth, rounded port that is angled forward and lays very evenly and softly across the tongue. It is great for the horse that hates too much tongue pressure. This model has 7cm shafts (more common size) in stainless steel with either aurigan or sensogan metal center. We also stock it in 14mm and 16mm thickness and both thicknesses in either 7cm or 5cm length shafts.
Sizes are transposed:
5" = 125mm
5.5" = 135mm (between 5.25 and 5.5"; closer to 5.5")
5.75" = 145mm