Uploaded August 2026 | Updated September 2026, 3 weeks ago

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convoylight.com/products/convoy-l21b-black-21700-flashlight

Conclusion for translation

Pros:

+ Regulated buck driver
+ High sustained output
+ Excellent output & range
+ Build quality
+ Lightweight
+ Beam profile
+ Price

Cons:

- Positive DUV on my LED, quite green
- Runs hot, sits at 63°C (similar to SFT42R)
- Stock 22mm driver has a bug, see note

The graph shows the F45R running for longer on turbo before thermal stepdown, for some reason the driver in the SFT42R unit stepped down at only 43°C, whereas the F45R stepped down at 54°C. Taking this into account there's little difference between them.

Note: I swapped in the 17mm 10A buck driver for both units, there's a 17mm - 22mm adapter available from the Convoy store for this mod. The 22mm driver is bugged and steps down to 80% output at just 30 seconds.

The square gasket around the LED is my own 3D printed.

Chapters:

0:00 Intro
0:08 F45R LED
0:10 Graphs
0:17 Range 150m w/ Measurements
1:00 Range 95m - 510m
2:12 Comparison Photos
2:35 Conclusion

Music:

Punch Deck - Lost In The Void
youtube.com/watch?v=FfFBgGbae48
punchdeck.bandcamp.com/track/lost-in-the-void