Up for review is the Xtar TZ20, a budget weaponlight.

Here is a summary of the specs from the manufacturer's website:

• Cree XR-E LED (Q5) with lifespan of 50,000 hours
  
• Max output 240 lumens; one mode of output
  
• Powered by 2 x 3V CR123A/ 2x RCR123A Lithium/1 x 18650 Li-ion battery
  
• Premium Type III hard-anodized anti-abrasive finish
  
• Accessories included: Lanyard; Body clip; standby Tactical ring; Two spare O ring circle; Weapon mount; Remote pressure switch
  
• 140.5mm (Length) x 25.00mm (Diameter) x 34mm (Head)
  Note: the light was provided by Xtar for evaluation.
  here is the light:
  
  the light comes in a nice box with a plastic insert containing the light and acessories
  
  
  the lights are pictured with the grip ring removed,
  
  
  here is the light with the pressure switch attached.
  
  
  and here is the light with the weapon mount attached.. sorry, I do not own any firearms to attatch this to.
  
  
  
  
  
  
  
  
  xtar uses square threads on this light.. square threads are more expensive to machine, but are much harder to cross-thread
  
  
  
  Size Comparisons:
  
  
  Comparison Beamshots:
  
  
  
  White Wall Shots:
  Shutter Speed is not specified -- the white wall shots are meant to show artifacts, rings, etc in the beam, not for brightness comparison.
  
  
  
  Outdoor Beamshots:
  Xtar TZ20 1x18650
  
  
  
  Runtime:
  
  the light doesn't look to be the most regulated light ever.
  
  Impressions
  The TZ20 is Xtar's first attempt at making a weaponlight. As a first try, they do decently, but I think there could be many improvements to the pressure switch. Having handled surefire pressure switches/ weaponlights (660), I can say that the xtar switch is not as high as it could be, First of all, when the pressure switch is used, the only method of activation is through the pressure switch. In contrast, the surefire tape switch has an additional switch on the tailcap to allow for an extra way of controlling the light (or, if you want constant on), and the pressure switch is detachable. The pressure switch itself feels slightly cheap, consisting of heatshrink plastic. Then again, I may be comparing apples and oranges. The surefire weaponlights are 5x-10x more expensive than this specific product.
  
  Back to the light itself. The light is easy to grip, but the screw-on clip makes it less comfortable than it could been. The clip is best left unremoved, as there are 2 holes in the light that are vulnerable to the elements underneath. In my opinion, the grip ring was also uncomfortable, but it is easily removed, and replaced with a ring that is included. the light is pictured without the grip ring in all the pictures above.  The light is otherwise designed well, and feels high quality.
  
  As expected, brightness is on par with most of the decent XR-E lights out on the market. The light, though is slightly cut off from the stainless steel ring on the head, though, In my opinion, it is a good tradeoff for the durability the ring offers.
  
  At the moment, I think this light is a good deal with all the acessories included. I am unsure whether to recommend it in a true tactical application, as the tape switch does not feel all that great. YMMV.
  
  As of [1/16/2010], the price of this light is roughly 40$. It can be purchased at Sbflashlights.com