"Two is one, and one is none; but three is better" is a popular motto amongst survival enthusiasts; So I was thinking... On my keychain I have my small kit: a Victorinox Classic SD knife and Fenix E05 flashlight, on my belt I've got my medium kit: a Victorinox Workchamp knife and Fenix PD20 flashlight; but in my bag I only had a larger knife: the Helle Fjellkniven. Time to go shopping!
My criteria were clear: I wanted a flashlight that could do 18650 as well as two CR123a batteries, it had to do at least 380 lumens (double that of the PD20) and it had to be a "tactical" light; which basically means that the on/off switch also has a momentary on position. Many flashlights caught my eye, but eventually my selection narrowed down to a choice between the to the Fenix TK21 U2 and the Olight M21 "warrior".
The Fenix TK21 U2 puts out 468 lumens and is priced around the € 95,- where the Olight M21 puts out 500 lumens and is priced around € 110,-. The prices are those of web shops in the Netherlands, and as most people in the Netherlands know; stuff is usually cheaper in Germany; so I decided to browse a bit on the German EBay site. I saw a Danish web shop that sold a brand new (sealed package) Olight M21 for € 35,- plus € 25,- for shipping. Their explanation for the low price was that they were clearing out the warehouse for a new collection. I don't care what the reason is... this was my chance to get the Olight M21 for half the price! My choice was made on the spot. About a week later (today), the postman came knocking on my door
As mentioned before, this bad boy put a whopping 500 lumens maximum with just one 18650 battery (or two CR123 batteries), and can do that for about 75 minutes nonstop; which is quite impressive. It's a very high-end flashlight, and you can really tell; it's built like a tank! It comes into play with small details like double O-rings, long threads for the screw-on caps, etc... the fit and finish is just perfect.
The user-interface is pretty straightforward: the switch on the back turns the light on and off. Pressing the switch halfway means momentary on, and clicking it means the light will stay on. By twisting the head about 1/8th you cycle between output modes: low (20 lumens), medium (80 lumens), high (500 lumens) and strobe (500 lumens at 15 Hz interval). The light remembers the last mode it was in. So if you put the flashlight in strobe mode and turn it off, it will come back on in strobe mode; even with the momentary switch.
One of the reasons I wanted a flashlight that could also run on two CR123 batteries, is the fact that my Fenix PD20 also uses CR123 batteries. So by keeping three spare CR123 batteries in my bag, I have flexibility in my lights: At full capacity I can run the Olight M21 at full output for 2.5 hours (2x 75 minutes) and the Fenix PD20 for 4.5 hours (2x 140 minutes); or I could run the Olight M21 for 75 minutes and then have the Fenix PD20 run for 9.3 hours (4 x 140 minutes).
Alternatively, if I don't need a lot of output but want sustainability, then the numbers become somewhat ridiculous... I could run the Olight M21 at 20 lumens for 30 hours till the 18650 is empty, then have the Fenix PD20 run at 10 lumens for a whopping 264 hours (66 hours per CR123), and then squeeze another 6 hours of 30 lumens out of the Fenix E05 on my keychain (3 hours per AAA battery). That's a grand total of 300 hours (or 12.5 days) of non-stop light out of my EDC kit