The Durkin Precision 15? Free Float M-Lok Handguard is a lightweight and comfortably slim handguard ideal for shooters wanting to keep unnecessary ounces off their build. Each rail is precision machined from high-strength aluminum and features a tough hardcoat anodized finish. With a comfortable 1.375? internal diameter & 1.5? outside diameter this M-LOK compatible handguard is an excellent option for your next build.