Smallsun ZY-T66
Reviewer’s Overall Rating: ★★★★☆
Summary:
Battery: 18650
Switch: Reverse clicky
Modes: H/M/L/Strobe/SOS
LED Type: XM-L T6
Lens: Glass-non-AR
Tailstands: Yes
Price Paid: $15.27 shipped
From: Wallbuys ZY-T66
Date Ordered: January 10, 2012 Received first week of February
This is my first review so any tips or help would be appreciated. 
Pros:
Good build quality.
Nice even anodizing that matches on all parts.
Tail stands.
Clicky feels good.
Very useful beam, good spill, not very ringy for smooth reflector.
Glass lens.
Smooth, clean reflector.
Single 18650 battery.
Good heat-sinking.
I like the coffee color.
Well machined anodized threads.
Tail cap lock out feature.
Quality machining.
Cons:
Only driven at 1.7 amps before resistor mod.
I’m not a fan of using a spring to conduct current from ground ring of driver to light body.
I like knurling to be much more aggressive.
Features / Value: ★★★★☆
I ordered the ZY-T66 from Wallbuys during their New Year’s sale and paid $15.27 for it. At that price I think it’s a heck of a deal. It normally sells for around 22 bucks. It feels good and solid in hand.
Design / Build Quality: ★★★★☆ Build quality is quite good even without considering this is a $20 flashlight. The machining is nice. Even though I prefer more aggressive knurling, because of the shape of the light it doesn’t affect your hold. For a light this size there is a lot of mass for heat sinking in the body and head. The aluminum pill is about 24mm in diameter and 15mm tall. It takes a 20mm driver and appears to also take a 20mm star. There is an LED locator to assure centering, but the star has been glued down to the pill from the factory so you don’t have to worry about it. The LED centering piece also insulates the aluminum reflector from the driver. Another neat item is at each end of the battery tube is a brass insert to assure good contact between the body, switch, and driver.
Brass inserts at each end of battery tube.
Pill Holder
Pill LED side
Pill driver side
Battery Life: ★★★☆☆
I didn’t do any run-time testing, but stock the driver pulls 1.7A at the tail-cap. That should give you around an hour and a half run time on a 2500mAh battery.
Light Output: ★★★☆☆
Stock the light output was rather mediocre. If I remember right it tested a little over 500 lumens doing a ceiling bounce test in my little bathroom. I soldered a 22g wire up the middle of both springs to reduce resistance. I also added another sense resistor and these mods brought the current up to 2.5A. Given the heat sinking of the light, I think you could crank it up to three or even three and a half amps, and plan to do so in the future. Now the hot spot is more intense and I estimate about 650 lumens OTF. Using a CT-1330B light meter, I measured 2330 lux at ten feet. Converted to one yard gives 25,880 lux. That gives it an ANSI throw rating of 322 yards. Not bad for a 38m reflector. The tint is almost pure white with a slight blue visible in the spill when white wall hunting. In actual use I never noticed the cool tint.
Wires added to springs to reduce resistance
Lux at 10 feet is 2330
Summary: ★★★★☆
I really like it. Most of my other lights are more geared to EDC use, my favorite being a 14500 powered, 8x7135 driven XM-L. Now you can carry this in your pocket easy enough, but it is no UF2100. For use outside though it excels. With a couple minor mods it throws pretty well, has usable spill, doesn’t weigh a ton, and can be slipped into your pocket. If I’m checking around the house and yard at night, this is what I grab.
Budget Light Forum …where Frugal meets with Flashlight!