Reinsman argentine bit with 7/16" smooth sweet iron single joint mouthpiece. 6" cheeks with 4 1/2" mouth. 
 
"Excellent transition bit from a ring snaffle to introduce curb pressure. Low leverage but added curb pressure gives more control. Packs easily. Sweet iron is intended to rust and promotes salivation for a supple feeling mouth. Mullen relief mouthpiece creates even pressure across the bars and tongue to eliminate nutcracker effect."