ACR C-Strobe LED PFD Light and C-Strobe LED Auto H2O PFD Light Models: C-Strobe LED Manual PFD Light (Model 3965.1) C-Strobe LED Auto H2O PFD Light (Model 3964.1) Product Description The ACR C-Strobe LED PFD Light (3965.1) is a compact, slim, and lightweight personal flotation device (PFD) light designed for location assistance in low-light emergencies. It features a bright 45 lumen white LED with three modes: strobe, steady-on, and SOS. The light offers more than 120 hours of continuous operation in strobe mode and is manually activated via an easy twist On/Off mechanism. It is waterproof (tested for 24 hours at 3.3 feet) and housed in an impact-resistant case. The device is USCG and SOLAS approved and fits easily in a pocket or attaches discreetly to life jackets, backpacks, or other gear using its lashing loops, Velcro strap, or clip for oral inflation tubes. The C-Strobe LED Auto H2O (3964.1) shares similar features but adds automatic water activation sensors that turn the light on upon contact with water, in addition to manual activation. It offers the same 45 lumen LED and 3 modes of operation with an extensive runtime exceeding 120 hours in strobe mode. Like the manual model, it is waterproof with electronics housed in an IP68 water-resistant light head, and has multiple mounting options with lashing loops, Velcro strap, and inflatable life jacket clip. Comparison Table Feature C-Strobe LED PFD Light (3965.1) C-Strobe LED Auto H2O PFD Light (3964.1) LED Brightness 45 Lumen White LED 45 Lumen White LED Modes Strobe, Steady-On, SOS Strobe, Steady-On, SOS Activation Manual On/Off twist Manual On/Off push or automatic water activation Operation Time >120 hours continuous strobe mode >120 hours continuous strobe mode Waterproof Tested 24 hrs @ 3.3 ft (1 m) Tested 24 hrs @ 3.3 ft (1 m) Battery Type 2 x AA 1.5V (sold separately) 2 x AA 1.5V (sold separately) Certification USCG / SOLAS / CE / Transport Canada USCG / SOLAS / CE / Transport Canada Case Impact resistant Impact resistant Size (L x W x H) 5.56" x 1.38" x 1.2" (14.1 x 3.5 x 3.0 cm) 5.56" x 1.38" x 1.2" (14.1 x 3.5 x 3.0 cm) Weight Lightweight Lightweight Mounting Options Lashing loops, Velcro strap, oral inflation tube clip Lashing loops, Velcro strap, oral inflation tube clip What’s in the Box C-Strobe or C-Strobe Auto H2O light Lanyard PFD Clip Velcro strap