Safariland 6378RDS ALS Holster Glock 19 MOS Gen 3-4 SureFire X300U

The Safariland 6378RDS ALS holster delivers secure retention and rapid deployment for Glock 19 MOS pistols equipped with SureFire X300U tactical lights. This paddle holster combines Safariland's proven Automatic Locking System with red dot sight compatibility for modern defensive applications.

What Makes This Different

The ALS (Automatic Locking System) secures the firearm immediately upon holstering without requiring manual activation of retention devices. Unlike traditional thumb break holsters that rely on leather or fabric straps, the ALS uses a rigid internal mechanism that locks onto the trigger guard. The open-top design accommodates red dot sights and suppressor-height iron sights without modification.

Key Features

• Automatic Locking System engages trigger guard for Level I retention
• Accommodates Glock 19 MOS Gen 3-4 with mounted SureFire X300U light
• Open-top design clears red dot optics and tall sights
• SafariLaminate construction resists scratches and impacts
• Paddle attachment system with adjustable cant angle
• Suede lining protects firearm finish during draw cycles
• Right-hand configuration for strong-side carry

Field testing demonstrates consistent sub-second draw times while maintaining positive weapon retention during physical activity. The holster performs reliably in temperatures from -40°F to 160°F and resists chemical exposure from cleaning solvents and lubricants. Law enforcement agencies have documented over 50,000 successful draw cycles without mechanical failure of the ALS mechanism.

Technical Specs

• Compatible Firearms: Glock 19 MOS Gen 3-4
• Light Compatibility: SureFire X300U series
• Retention Level: Level I ALS
• Material: SafariLaminate thermoplastic
• Mounting: Paddle system with belt loop adapter
• Cant Adjustment: 0° to 15° forward
• Color: Black finish
• Weight: Approximately 4.2 ounces
• Country of Origin: United States

This holster addresses the specific needs of shooters running weaponlights with optic-equipped pistols. The combination of passive retention, sight clearance, and proven durability makes it suitable for duty carry, competition, and personal protection applications.