Rugged Suppressors R3L Flash Mitigation System Long Flash Hider .300 Remington Ultra Magnum 5/8x24 Black RH003. Our R3L utilizes our snag-free toothless Dual Taper Locking System making it compatible with all of our rifle and multi-caliber suppressors. The R3L has a .30 caliber aperture making it compatible with rifle calibers up to .300 RUM Specifications for Rugged Suppressors R3L Flash Mitigation System Long Flash Hider: Manufacturer: Rugged Suppressors Color: Black Caliber: .300 Remington Ultra Magnum Threads per Inch: 5/8x24 Length: 2.58 in Weight: 3.4 oz Condition: New Features of Rugged Suppressors R3L Flash Mitigation System Long Flash Hider: Snag free Package Contents: Rugged Suppressors R3L Flash Mitigation System Long Flash Hider Rugged Suppressors RSFH003: R3 5/8 X 24 Long Flash Hider Black