I was asked by Tracy at Sofirn to review a couple of lights. This first one is the SP33, a new side switch light with lighted battery level indicator in the side switch, similar to some Thrunite lights and the UTorch UT02.
The AliExpress store listings show it HERE in the $25 range, a good deal for this light in my opinion.
The AliExpress site above shows it coming with a cell and a small single cell charger… I didn’t receive those with this sample light but it did come in the nice box shown and it has the adapter sleeve to allow use of 18650 cells.
Below is what they say about it on the site…
Notice：Turbo brightness level automatically turns to High brightness level after working 5 minutes, so the running-time of Turbo brightness level is accumulated time.
The tail could not uncrew (note from DB, the tail cap is glued on, probably to keep the spring captured)
Specification:
※ Use CREE XP-L LED with a lifespan of 100,000 hours.
※ Correlated Color Temperature Range(CCT Range): 5350K-5700K, NW
※ Working Voltage: 2.8-4.3V, Max Current 3A
※ Battery Supported: 1pcs 18650 Battery or 26650 Lithium batteries
※ Dimension: 124mm(length)× 31.5mm(diameter) × 36mm(head)
※ Net Weight: 70.8 gram (no batteries included)
※ Mode Memory : Yes
※ Smooth Reflector
※Made by Aircraft 6061 grade-aluminum alloy, used CNC machines, Premium type Ⅲ hard-anodized anti-abrasive finish to get solid built body, anti-crash and better heat exchange
※ Toughened glass lens with AR coating, anti-crash and wearable
※ The waterproof level is IP68, it can be used in rainstorm.
※ Lock-out function: to avoid accidentally activating flashlight in pocket or handbag
Off : Please double clicks the side switch to lock, the signal is that the light flashes twice times.
OFF and Lock out: please double clicks the side switch to unlock. The signal is that the light turn on in a previously used mode.
※ Smart Power Indicator (on the side switch):
Green Light: the battery capacity > 50%;
Orange Light: the battery capacity between 50% and 20%
Red Light: the battery capacity <20% (please recharge or replace the battery )
※Low Voltage Protection: lower than 2.8 Volts, the flashlight turns off automatically to avoid over-discharge. If then reactivate it, the Low Voltage protection function does not work.
Operation:
The side switch to control all function:
1, To press the side switch for 0.5 second to turn on or turn off;
2, click the side switch to cycle through LL→Low→Mid→High→Turbo.
3, When unlock, three clicks to turn on”Strobe”, and one click to turn back.
4,Lock-out function:
When the light is off, please double clicks to activate the “Lock-out” function, “lock-out” works when the light flashes 2 times.
When the light is lock-out, please double clicks to unlock, then the light turn back to the previously used mode.
Warning
LED flashlight is high intensity lighting, and equipment can cause eye damage, avoid direct exposure to the eyes.
The emitter appears to be a Genuine Cree XP-L HD, it’s probably a 3C tint as it’s a very nice Neutral White in color.
This is a nicely made light, the finish is clean and well done, the knurling is grippy without being sharp, overall fit and finish are as good as any light you’re likely to receive from anybody… albeit not the matte finish of some.
The reflector is well made and the beam profile is much to my liking with a defined hot spot, gentle aura, and notably faint spill. Very useful in a lot of general application type scenario’s.
I got these numbers from a LiitoKala light blue 5000mAh 26650…
0.02A for 15.08 lumens
0.12A for 53.13 lumens
0.52A for 212.52 lumens
1.48A for 545.79 lumens
3.31A for 1097.1 lumens
Strobe seems to be on the level of the highest output and is hidden behind a double click when on.
I’ll be disassembling this to show how it’s put together and show the driver, will be back with pics on those details…
At this point, I have to say this one is a well made light and I like it quite a bit. 
Thanks Tracy, job well done!
Dale
Back, after disassembly… first thing to point out is that the spring in the tail is a large one and it’s captured by the tail cap so it stays in place. With the tail cap glued pretty solid, reckon I won’t do a bypass till my neck is better. (can’t crank down on trying to unscrew it without pain. 
)
The next thing to point out is that the driver retaining ring is left-hand thread, turns to the right to remove. This is good, seeing as how you have to unscrew the battery tube to get to the cell. The threads are separate from the tube threads, which is how this works out.
I don’t recall ever seeing a driver quite like this one… it’s pretty nice and easy to get to and the sense resistors add up to 0.02185 ohms in stock trim. This is at 3.31A tail current, notable
Check out the MCU on this one!
This is a Stainless Steel bezel that fits down over the top of the reflector, with the lens pressing the o-ring into a shelf at the outer top edge of the reflector. Well made, a bit difficult to reassemble as the o-ring is on the small side.
The mcpcb is copper, but not direct thermal path.
Inside the driver bay… note that the vertical pcb which holds the switch is slotted into the bay so it won’t be able to be pressed askew by the switch. Nice stable set-up. Well done!
Ok, so with regulated drivers you have to be careful bumping them as it doesn’t take much sense resistor change to blow the driver. I stacked an R100 on top of the R068/R040 combination and this lowered the resistance to a total 0.020118 (down from 0.02185). Not much less, but enough to gain 2A at the tail! 
(also put a 22ga wire bypass on the driver spring)
Now I get readings like this, with the XP-L emitter transferred to a BLF Special Edition Alex Wells DTP 16mm mcpcb….
0.08A for 20.7 lumens
0.22A for 73.49 lumens
0.81A for 298.77 lumens
2.34A for 769.35 lumens
5.31A for 1566.3 lumens
Now THAT’s more like it!
I like this one, quite a lot actually. Hope y’all find it as well made and easy to use as I do!
Dale
