The MS-2000 (M) distress marker light has come a long way since you purchased ACR's original Firefly back in the 1960s.

Here are a few of the new features found in all of our MS-2000(M) models:
Shield extends/retracts for omni- or uni-directional visibility

Waterproof down to 50ft (15.3m);

IR filter blocks all visiblelight (lets through only IR light)

Raised polarity indicators allow correct battery replacement in low or no visibility conditions

New braided steel retainer keeps battery door from being lost

Operates on 2 standard alkaline AA batteries - disposal causes no environmental impact

For extreme cold environments or long term storage, use 2 common lithium batteries

Blue filter distinguishes strobe from ground fire when in place

Specifications

Size: 4.5 x 2.2 x 1.1 in (11.4 x 5.6 x 3.3 cm)

Weight: 4.0 oz (115 g) without batteries

Light Output: 250,000 peak lumens per flash

Flash Rate: 50 ?? 10 per minute

Light Dispersion: White-omni directional, IR-omni directional, Blue-unidirectional

Operating Life: 8 hours minimum-strobe; 2 hours minimum-incandescent

Visibility: Military tested at a distance of 6 miles (9.6km) on a clear dark night

Waterproof: To a depth of 50ft (15.3m); 200ft (61m) diver version available

Batteries: 2 AA alkaline or lithium batteries (not included)

Case Color: Black with olive drab flashguard

Construction: Case, lens and flashguard-high impact polycarbonate; IR filter-butyrate

Activation: Spark proof magnetic reed switch

Limited Warranty: 1 year