Kinfire K40X
Reviewer's Overall Rating: ★★★☆☆
Summary:
| Battery: | 4 x 18650 |
| Switch: | Electronic side switch |
| Modes: | 3: High, Low + hidden strobe |
| LED Type: | 4 x XM-L2 (Cool White) |
| Lens: | Glass |
| Tailstands: | Yes |
| Price: | $43.63 Shipped |
| Provided by: | GearBest for review |
| Product Link: | http://www.gearbest.com/led-flashlights/pp_5508.html |
Pros:
A bit more compact compared to my SRK sample.
Versatility in Battery options (1 - 4)
Very bright, I would estimate around 2500lm.
XML2 emitters, cool white.
Great Run-time with 4x 18650 in parallel.
Electronic side switch with hidden strobe.
Exterior/machining/thread quality is good.
The extra machining work makes it more comfortable in your hand.
Cons:
No substantial heatsinking, just a thin quad-LED MCPCB/star resting on a small ledge. More on this later.
Defect in one of the reflector wells.
Very tiny wires utilized (Could be a good thing considering the lack of heatsinking)
Incompatible with flat top batteries (Laptop pulls need solder mound added to positive terminal)
Slight audible whine in Low mode.
Longer protected batteries are a very tight squeeze, so much so that I would only recommend using flattop cells.
Positive terminal of batteries rub against the driver contact board when tightening the battery tube (This could be an issue in the long run, and is a much greater issue in the K40X vs my SRK)... more on this later.
A bit on the heavy side loaded with 4x 18650.
Came bundled with 4x Kinfire BRC 1500mAh cells, all measuring below 1v. Didn't bother taking the risk to charge them.
Incorrect specifications:
The glass lens does not have AR coating.
The Flashlight received is Silver, but listed as brown, black, or gold (I like the silver, but requested brown).
The throw is not 300-400m, reasonable estimate would be a usable brightness around 75-100 yards.
Pictures:
Open any image to view full resolution!
This box arrived in a reasonably padded bubble mailer.
Inside the box, loose accessories. :(
Here are the contents of the box. The cells measured less than 1v each. I decided it was not worth the risk to attempt to charge them, even in a controlled safe area.
Despite the packaging, the light arrived unharmed.
The bezel is aluminum, poorly coated. The inner area of the bezel has splash marks and some slight machining marks. They can be seen better in the emitter picture.
Here are the 4 beautiful XML2 emitters. A few are slightly off center, this doesn't seem to effect the beam pattern in a noticeable way.
You can see the machining marks and coating defect on top of the bezel.
Size Comparison:
From left to right: K40X, SRK, Solarforce L2, Tangsfire C8
Comparison with SRK:
(Kinfire is always on the left, SRK is always on the right)
Tailstand
Headstand
A peek at the bottoms
Emitters (XML2 in the kinfire, XML in the SRK)
One of the big differences is the battery tube length.
This reduced length in the Kinfire K40X causes a problem with longer (protected) cells.
Cells from left to right in the Kinfire battery tube: 2x Laptop pull w/ brass nut, laptop pull with small solder mound, Panasonic protected NCR18650B 3400mAh
(This mix and match cell configuration is for visual demonstration purposes only... DO NOT mix and match cells for usage)
View from above
Cells from left to right in the Kinfire battery tube: 2x Laptop pull w/ brass nut, laptop pull with small solder mound, Panasonic protected NCR18650B 3400mAh
(This mix and match cell configuration is for visual demonstration purposes only... DO NOT mix and match cells for usage)
The picture below is regular use, laptop-pull cells.
Disassembly:
Top of the battery tube threads. Nice, Smooth and lubricated.
Bottom of the battery tube, 2 of the screw holes are bare and not drilled.
Underside of the head, backside of the driver.
Plain glass lens, aluminum bezel, switch retainer, switch button, thick O-ring, aluminum reflector.
Small defect in the reflector (Upper left hand well)
Quad emittter MCPCB
Nothing underneath. 
A look at the driver and the extremely thin wires.
Conclusion:
Based on preliminary beamshots I would rate the Kinfire K40X at 3/5. The major deductions mostly come from the lack of heatsinking, less than optimal driver, and the short battery tube. It does still output a decent amount of light, but the lack of heatsinking is going to be a problem if one wanted to mod and could be problematic for the LEDs in the long run.
