Please note that this is the flood version of the H51 and the specs below are for the regular H51. The H51F has a frosted lens, which does a great job of smoothing out the beam and making a very nice flood light, but it greatly reduces throw.
Main Features and Specifications
LED: CreeÂ XP-G Cool White (color temperatureÂ 6100-6500 K)
User Selectable Modes: 3 (High, Medium and Low). Each mode can be configured to one of the two sub-levels.
High:Â Â Â Â Â Â Â Â H1Â 200Â Lm (0.9 hrs)Â Â orÂ Â Â H2Â 100 Lm (2.1 hrs)
Medium:Â Â Â M1Â Â 30 Lm (12 hrs)Â Â Â orÂ Â Â M2Â Â Â Â Â 8 Lm (39 hrs)
Low:Â Â Â Â Â Â Â Â Â L1Â Â 2.5 Lm (3Â days)Â Â orÂ Â Â L2Â Â Â 0.2Â LmÂ (19 days)
Light output are out the front (OTF) values. Runtime tests areÂ doneÂ usingÂ Sanyo 2000mAh Eneloop AA batteries.
Voltages: 0.7V - 2.5V
Battery: OneÂ 1.5V AAÂ (NiMH,Â lithiumÂ orÂ alkaline). 14500 Li-ion batteries are not supported. Batteries are not included in the package.
Parasitic Drain:Â Negligible (equivalent to 16 years)
Diameter:Â 0.90 inchÂ (23 mm)
Length:Â Â Â Â 3.2 inchÂ (81 mm)
1.2Â oz (35.8 gram)
2.2 oz (61.9 gram) with an Eneloop AA
3.0Â oz (84.9 gram) with an Eneloop AA and headbandÂ
Electronic soft-touch switch, with a 200,000 cycle operating life
Smart user interface provides fast and easy access to allÂ brightness levels
Precision machined unibody casing from premium grade Alcoa aluminum bar stock
Proprietary heat sinking design bonds theÂ LED board directly to the unibody aluminum casing, providing unblocked thermal paths to over 94% of the surface area.
Durable natural hard anodized finish (Type III Class I)
SCHOTT ultra clear lens with anti-reflection coatings on both sides
Orange peel textured reflector
Glow In The Dark (GITD) silicone ring near the tail cap
Battery power can be locked out by slightly unscrewing the tailcap to prevent unwanted activations
Waterproof to IPX8 (1 meter 30 minutes)
Short click turns on the light to HighÂ instantly. Click again quickly to cycle from High to Medium, and Low.
Press and hold to cycle through Low, Medium and High, release to set.
Short click turns off the light.
Press and hold to cycle from Low toÂ High, release to set.Â The lightÂ always cycle from Low to High regardlessÂ whichÂ level you are currently in.
Double click at any level to toggle and selectÂ between the two sub-levels for that level.Â Medium and LowÂ selections are memorized after the light is turned off and through battery changes. H1 is not memorized.