It’s pretty stretchy, feels like the same as what’s on my other headlamp straps that don’t go over the head. I think the “around” part would hold it sufficiently as long as you’re not jogging with it.
That’s good to know. I hate jogging so that’s not an issue. 
I just don’t like something going over my head like that if it’s not necessary. It also makes it take up a lot more space when not in use.
I have plenty of time to think about these things since apparently I won’t get it for 25 days or so. I haven’t ordered from China in a long time so I’d almost forgotten how long shipping times can be.
I too would like to see version 2 come with a lighted switch that is on when the main LED is off. Or, have a 'breathing' feature like the Sofirn SC31. As I'm looking at the pictures, the head seems to be the main physical difference between these two rechargeable models.
Heck, after reviewing your (G's) Review, Sofirn should just copy, but with higher output, the driver in the SC31. Output curve looks more in line with the performance commentators here are asking for.
I've gifted or sold all my SC31s but I'd keep what I'm calling a headlamp version of the SC31. It might be updated it with a high CRI SST20 as the temperature regulation would protect it.
Sofirn, perhaps you could bring this all together in V2. V2 might be cheaper to boot!
- Agree! A high CRI>95 version of 81650/21700
- Current version is L shape, capable of use on head or edc. Next version, I say probably had been better and nicer if it is design like T shape like Acebeam, D10/D25/D25s. T shape is supposed to be a dedicated headlamp only.
- Temperature control and heat sinking fins(like D25s)
- single head/doublehead/triple head?(just consideration…)
- bike mounted?possible bring “them” in along…
I got mine today from Amazon. I like it. I haven’t tried it outside at night yet. The USB charging option is a nice touch.
Did you ever see the driver on this one or do any of your MCU mods?
I’ve been meaning to but haven’t yet… too many on-going projects 
(oh, and a new baby any day now, so that might slow things down a bit)
New babies cant get too far away from the modding table until they are much older, no worries! Congrats
Exciting! Congratulations.
Oh, no. More people? How does this keep happening?
Thanks for the review. I just ordered one with Sofirn’s discount code. Should have it in three days. Looking forward to it.
My only other 18650 headlamp is a cheap zoomie with only two brightness levels plus strobe and has a bluish tint.
You betcha I know, and I have no plans on stopping that act until I’m 6 feet under. 
:+1: Cool. Especially with where you’re coming from, I think you’re really going to like it!
To anyone interested, I posted my impressions about the SP40 in a separate thread.
I got mine today.
First impression is that I don’t like the UI.
Prefer the UI of either the SP32A V2.0 or D25S.
I’m curious what in particular you’re not fond of about the UI? (sincere question, not being a jerk)
Main differences I see between the SP40 and the D25S: the D25S has one additional brightness level, turbo is in the normal rotation, and it has hidden strobe/beacon modes.
The SP32A OTOH, it has the 2 groups: defined modes and ramping. Options like that are great for sure.
The D25S ramp goes forward or backward, rather than forward only, which I prefer.
The button on my SP40 also seems a bit stiff, which makes holding it to ramp a bit difficult for me.
I read this like an xkcd comic.
Gchart, first of all, congratulations on your family's new addition!
I was thinking about holding off on buying this light but then there was that blessed Vipon discount code. Anyway, somehow, I got the code and wham!, I've got a new addition, too 
.
When I got it, my question was how fast (rate & time) does it charge the battery in light(?). With the Sofirn stock batt., this is what I found:
Charge rate along with other parameters,
https://i.imgur.com/uOP5LFy.jpg
And, ultimately, the results,
https://i.imgur.com/D62iBnZ.jpg
I first discharged the battery with an Opus I keep at work so started this charge cycle in the evening. 0.9A isn't too slow but I'm a bit miffed at this taking 5 hours. I guess I'm used to charging with the MiBoxer at the house. If anyone here is familiar with these 'cable testers' you might shed some light about the charge time. Like the OP review findings, the end voltage was around 4.17V.
I've read some fairly negative comments where Sofirn could have added UI features like the SP32A and/or SC31 and I'd like those too. SOFIRN, SEND ME THE VERSION 2 FOR A REVIEW!
But I'm happy with the beam pattern, tint and definitely the 18350 tube. The beam angle is so wide, it's like a mule with a hop spot!
The Sofirn 3000 mAh is curretly in the MiBoxer to compare results between charge options. More to share...
I did a discharge test at 3.5A with the battery and got 29xx mAh. Seems like the battery is as advertised.