NRS 1-1/2" x 1-1/2" Ported Chain Horse Bit We have taken one of our most popular bits, the NRS Chain Bit, and added another great option! Handmade by Tommy Blessing, this bit incorporates the popular chain mouth with a 1-1/2" floating port in the center. This gives the rider more response and for stopping and flexing while maintaining the forgiving features of the chain on the bars of the horse’s mouth. A great addition to any collection.