Manufactured from sturdy 17-4 stainless steel, metal injection molded Unitek Miniature Twin brackets incorporate a micro-etched base for bond strength equivalent to mesh. Also featured are easy-to-read permanent I.D. marks plus new tie-wing ink marks. In addition, Unitek Miniature Twin brackets include a smooth, bi-directional hook for superior elastic engagement. Backed by 3M, the leader in orthodontic brackets and appliances for more than 60 years, Unitek Miniature Twin brackets promise outstanding performance for patients and practitioners alike.