The Perlick C649B Restrictor Kit is designed for use with 3/8", 5/16", and 1/4" beverage tubing, ensuring optimal flow control for your draft beer system. Each kit includes restrictor segments and tubing, 304 stainless steel splicers for durability, and stepless clamps for secure connections. Comprehensive installation instructions are provided for easy setup. Order one kit per beverage line to enhance your draft beer experience.