Dive deeper with your Sofirn SD05, a rugged, high‑performance flashlight built for serious underwater exploration, even in challenging currents.

Sofirn SD05 Diving Flashlight with XHP50.2 LED

The Sofirn SD05 is a rugged diving flashlight designed for serious underwater exploration. Built from aircraft-grade 6061 aluminum and finished with a premium Type III hard-anodized coating, this light stands up to the rigors of wrecks, caves, and strong currents while delivering reliable illumination when you need it most.

Note: The SD05 upgraded to the XHP50.2 LED in 2022, boosting brightness and efficiency without adding bulk, so you get deeper reach and longer runtimes in a compact form factor.

Why the SD05 stands out under water

• High-performance beam: Up to 2550 lumens with a maximum throw of about 244 meters, giving you crisp visibility in dark underwater environments and obstacle-rich passages.
• Battery versatility: Accepts one 21700 or one 18650 Li-ion cell. The 21700 battery-kit option increases capacity for longer dives, while the base model keeps things compact.
• One-handed control in gloves: A magnetic rotating ring switch enables quick on/off and mode selection (Off, Low, Medium, High) without snagging gloves or causing water intrusion.
• Smart protection tech: Automatic step-down from High after 3 minutes to prevent overheating, low-voltage protection below 2.6V, and a low-battery warning that flashes rapidly when the voltage drops below 3V.
• Built for durability: 119 mm length, 37.5 mm head diameter, and 120 g weight (without batteries). CNC-machined from aircraft-grade 6061 aluminum with a Type III hard-anodized anti-abrasive finish for corrosion resistance and rugged use.
• Thermal management: Advanced Temperature Regulation (ATR) keeps the light from overheating, preserving LED life and maintaining safe dive performance during extended High mode runs.

Included with the 21700 battery kit

• 1 Sofirn SD05 flashlight
• 2 spare O-rings
• 1 lanyard
• 1 battery tube
• 1 user manual
• 1 21700 battery
• 1 USB charger

Ideal uses and who should consider the SD05

• Technical divers exploring wrecks, caves, or deep reefs who demand reliable brightness and consistent performance in challenging currents.
• Underwater photographers and videographers who need a strong, steady light source with a long runtime to capture scenes without frequent battery changes.
• Search-and-recovery teams operating in dim, open-water or cluttered underwater environments where precise beam control matters.
• Frequent night dives or cold-water dives where glove-friendly operation and robust construction reduce gear management hassles.

Practical tips for getting the most from your SD05

• Choose the 21700 kit when you anticipate multi-dive trips or extended expeditions; higher capacity translates to more consistent brightness over longer periods.
• Always pair with fresh or well-maintained batteries; avoid mixing old and new cells to prevent unstable output.
• Use the magnetic ring to switch modes before entering cool, cramped spaces to minimize handling time during critical tasks.
• Regularly inspect O-rings and keep the battery tube clean to maintain the light’s waterproof integrity during repeated dives.

Safety and care

Directly staring into the beam can damage eyes; always operate with caution. If the light detects a low voltage, it will shut off automatically to protect the battery and prevent unpredictable performance. When operating in High mode for extended periods, expect some warmth—this is normal and part of the light’s protective design.