Short to the facts: Four brightness levels of 1000, 400, 130 and 20 ANSI lumens, operating with 4 (2) lithium-ion battery of size 18650 or 8 (4) x CR123 batteries; a more / less to battery / batteries will only affect the operating time. Switchable strobe and SOS function, operation via 2 switches with clear pressure point; even with large hands / gloves precisely controllable.
It is supplied in a sturdy plastic box with carrying strap, instruction manual and spare O-rings. For normal delivery at the factory are neither Batteries or Charger. Processing appears properly; the threads are cut precisely and smoothly, the anodizing without error; the battery cage is made of plastic, makes a solid impression and fits perfectly without rattling etc. The lamp is protected against overcharging, over-discharging and overheating; the light intensity is electronically controlled constant. The lamp heats up not serious even at maximum output; Waterproof to IPX-8 standard.
The incredible high beam (Throw) is at only one XM-L2 U2 achieved by a special reflector; the TK 75 z. B. Although more ANSI lumens, however, is here coordinated with three reflectors on a good mix of flood and throw. Four circularly arranged 18650 batteries perform as in the TK 75 created a significant amount of the lamp body. The usable both in the TK 75 and TK 76 extension module (AER-TC 75) also does not lead to an increase in light output, but only to a doubling of operating time, where already the default configuration for around 4 hours of sustained in the highest level.
The completion of my standard headlamp tests (lamp mounted on a tripod, binoculars ZEISS 20x60 S without intensifier, alternatively ZEISS Diascope spotting scope 20-75x each on short tripod Bushnell Rangefinder) showed, even in lighted up at well over 800 meters, objects can not be properly identified.
Finally I would like to say something about the battery: If Ferrari probably no one would have the idea of raising four different cheap tires of different ages of differing air pressure. For batteries I've learned that some people only possible to buy "cheap" and take on several batteries per device, what is at hand.
CAUTION !! Lithium-ion batteries are not completely harmless. Who does not know this, should definitely inform the Internet. My rule: Only the same age and identical quality batteries from the same manufacturer and combine in the same state of charge.
The current price level for the TK 61 lies between 130.- and 200.- significantly above; each for delivery without batteries, rechargeable batteries and charger, plus possibly Porto. Sets with batteries / charger differ as strongly depending on the quality of the accessories.