Now available for milled models! Precision machined with maximum strength. Four mil-spec Picatinny rails for versatile accessory applications. Clever rail system locking design includes lower connecting walls mating with upper channels to achieve the most solid and secure fit- Lower quad-rail system to secure barrel Upper quad-rail system to secure gas tube Simple and friendly installation, no gunsmith or tool required. Great zero-retention capability for all accessories installed on the rails. Intensively tested by field experts under extreme heat and sub-zero temperature and demonstrates most satisfactory performance. Ultimate tactical solution to enhance accuracy under toughest environments. Fits model 47 and variants. Hard anodized finish for wear resistance. Great quality UTG rubber rail guards included for comfort and protection.