Instruction: Evaluate the answerability of a question by analyzing the related document, outputting yes if the document contains information addressing the question, and no otherwise.

Input:
Question: Is this a real Ultrafire flashlight or just a knock off?
Document: This is an Ok flashlight, it's not a real ultrafire, it's definitely a knock off and it's not a Cree XM-L T6, it's also a knock off, although almost as bright.The overall build quality is very poor, though as I said, it works, and for 9 bucks it's not a bad price. I don't expect this thing to last me very long.
You will note the lumens tested are greater than the LED emitter is capable of at max current rating by CREEs own specs. But these were real measurements and are useful only for general comparisons with my other flashlight reviews which use the same test method and is still on-going.
This LED flashlight is fine. It took some real finagling to get the periscopic focus ring to adjust like it should. In retrospect, I would have happily paid more money for an internal battery that could be plugged in. As it stands, I'll have to get NiCads. It works well and should last a good while.
I googled "Cree T-6" and went to Cree's website. Please understand, Cree Inc. is the American company that invented the particular Light Emitting Diode (the part that lights up like a light bulb) that is used in these flashlights, not the flashlights themselves. They have better things to do with their brains than run flashlight factories.The paragraph below is taken directly from Cree's website. (Efficacy is not a typo, it is a real word.
I have only had this flashlight for a couple of days, however, it is a GREAT flashlight. Construction is more than adequate, built out of substantial aluminum stock. Appears to use a real cree led, and have a good driver circuit. It is BRIGHT on high power, medium setting provides adequate light, and low is adequate for a stroll on a dark night to conserve batteries. This light is a good balance of light output to battery drain (how long before recharge, or replacement of batteries.)
I am very pleased with the Ultrafire 1000 lumens flashlight. It seems to be very well made, and it is particularly handy in that it is able to use three different type batteries.
This flashlight is bright. It is not as bright as the Ultrafire WF-501B but it is bright. It may be that because this has a magnifier in front of the cree light bulb that the light is spread more out towards the side. This then causes the central beam of light to not be concentrated in one spot and be as bright as it could if there were no magnifier in front of the cree light bulb.
I have used this flashlight only a couple times. I've, also, only had it for about a month. Now, when I use it, (holding steady) the light will flicker. Almost like there's a loose connection. Great light over all and the defect could just be from shipping. I am on deployment and the mail services are a bunch of military and civilian sailors. I do not blame the design on Amazon or Ultrafire.
I think this light is a great deal for the price. Some reviewers have complained it is dim. In my experience it's as bright as any Cree LED flashlight I own. I also have the Ultrafire 501b and 502b models that use the same Cree LED. This one is just as bright. The only quibble is that the beam isn't as uniform as those other Ultrafire models. I think this is the result of the "zoom" capability of this light. The optics aren't perfect.
When it works, the Ultrafire 1800 lumens is a great little flashlight. It came in a bag with no instructions! You'd think it wouldn't need instructions, but I had trouble using the AAA adaptor. I was unsure of which end to insert first! I tried both ways and neither way gave me results. The purchase wasn't so expensive that I'd bother to return it, so the next time I was out I went to Radio Shack because they have an answers for everything!!!!
Answer: yes