Review SingFire SF-501B

Light Brand and Model Number

Reviewer's Overall Rating: ★★★☆☆



Battery: 18650
Switch: Clicky
Modes: H/M/L/Strobe/SOS
LED Type: Cree XM-L T6
Lens: Glass
Tailstands: No
Price Paid: Free
From: Fasttech
Date Ordered: 09-15-13


  • It is budget. It goes for about $10 at Fasttech. It's very bright on high and it has a bright spot that is good out to about 60 yards. It takes a P60 drop in.


  • It's Cheap, so the quality is as good as a $10 light will get.

Features / Value: ★★★

The light has a good value for $10. It features an XM-L led and a 5 mode driver/no memory. It is bright as heck on high and it has a smooth beam. It will break down totally, so you could mod/replace any component easily.

Design / Build Quality: ★★★☆☆

Gold? Really? I'm sorry, but it just looks wrong in gold. It's gaudy and too much of a show off for what it is. Build quality is good for a $10 light and the design is fair. If the P60 drop in fit better into the head, then there would be good heat transfer, but it's not tight, so it does not transfer as good as it should.

Battery Life:

Not tested.

Light Output: ★★★★★

I believe it is direct drive on high. I measured 2.85 amps on high consistently and 3.4 amps on start up. It dropped to 2.85 in a few seconds. Can't ask for much more from a $10 light.

Summary: ★★★

Overall, it is probably worth the money, if you can accept the gold color. Fit and finish is good and better than many cheap lights. The threads are not square cut, but putting pieces together is smooth and with not a lot of drag in the thread areas. The lens is glass and the P60 drop in is ok, not bad, not good, just acceptable The fact that the light is so darned bright on high is what makes it a good light.

I have to state that the one I got was a freebie from Fasttech. I didn't even know it was coming. It arrived with an order from them. Unfortunately, the driver is not correct. The link to Fasttech states that the driver is H/M/L/Strobe and SOS. What I got was High/Low and Strobe. Three modes was all I got. High was 2.85 amps, Low was 125mA and Strobe was 1.4 amps. If the driver had worked as it was supposed to, I would have given it one more star.


They should be self explanatory. I just wanted to show the different components.


That is just dust. No defects in the reflector.


Damage on the tail cap.


Tail cap end of body. Threads were lubed.


Threads inside the tail cap are rough looking, but it screws on smoothly.


Body to head threads





Damage on the top edge of the Reflector, from a ring that holds the lens in and the reflector rubs against.



This is a cheap method of a contact plate, from the positive spring to the battery, but it works ok.


1 second shutter


1/4 second shutter, to show the hot spot better.

I ordered the purple one for my wife. It came in yesterday. I have ordered 501B’s before and this one is as good as any of them. At $10 it is a great bargain. There are 7 different colors of the SingFire 501B

Nice little light, thanks Justin. At $10 a pop, with some $1.08 18650’s from lap pulls, a dozen of these would make great gifts! (or 2-3, whatever) The beam profile looks nice with the hot spot diffusing into the spill. I much prefer that to a defined hot center area and low spill.

Thanks for bringing this one to my attention. Purple? Cool! Definitely have to check these out at FastTech! :wink:

I imagine I have spent $10 on worse lights…

What about the UltraFire WF-501B G74 900lm Xenon LED Flashlight Torch 18650? has it for sale for $5.77USD using coupon code ”bgaclf”. It says it has a xenon bulb lighting it. I don’t know how much of a difference it would be to the Cree emmitter.

I got a blue one and have been using it for the last few weeks with no problems…it looks cheap and feels cheap but works well. No complaints given the price

Thanks for the surprise review OL. Is the glass lens removable from the head?