Contents of the 4Sevens flashlight
1x 4Sevens Preon ReVO
1x AAA battery include
1x Key ring include
1x Spare rubber o-ring include
1x Instruction sheet include




The ReVO is the smallest member of the 4Sevens Preon line of lights. Up the front the ReVO has a smooth bezel, behind which sits an optical grade AR-coated glass lens. The aluminum reflector used to focus the light has a medium textured finish on it which should smoothen out the beam profile nicely. The XP-E LED sits almost perfectly centered at the bottom of the reflector cup. On the exterior the head has lines machined on running its length which provides sufficient grip which is good since the ReVO is a twist activated light. The best tactical flashlight bottom half of the head is made of brass and well-finished, threads are cleanly machined and mate well with those on the battery tube. A rubber o-ring sits just above the threads which serve as a moisture seal. A donut shaped piece of rubber is stuck on the rear end of the head serves as a physical reverse polarity protection for the battery. The battery tube makes up the second part of the ReVO and is almost completely covered in textured knurling with the addition of some flat faces machined where branding is printed. The rear end of the battery tube has a narrow rectangular lanyard attachment feature which has a rather wide opening so there’ll be no trouble threading in even thick para cords. Although this still allows the ReVO to tail stand, it won’t be very stable. On the inside, the battery tube is cleanly finished as well. There’s a tri-point contact for the battery’s “-” end. This contact has some tension to it so it also prevents the battery when rattling within the battery tube.

If you’re unfamiliar with any of the terms used in this flashlight review, you can search google for explanations on common flashlight related vocabulary.




The ReVO provides a total of 6 modes of output. From off position, switching it on presents the low output level. Subsequent off/on twists of the head within 2 seconds cycles through medium then high output levels. The remaining 4 output modes are strobe, S.O.S., and beacon. These are activated by going through 2 cycles of the low, medium and high output levels. So an overall sequence available is as follows:

Off to Low to Medium to High to Low to Medium to High to Strobe to S.O.S. to Beacon.

Take note that there is no memory functionality, so it will always revert to the low output mode first after the light is left off for anything more than 2 seconds.

Unlike some of the other 4Sevens lights, the ReVO doesn’t show any noticeable signs of pulsing at the lower output levels. The beam profile produced has a medium sized hotspot which tapers smoothly to the spill beam. Thanks to the textured reflector, the beam profile is nice and smooth with no artifacts. The best rechargeable flashlight output has a neutral white tint on this review sample. Runtime and regulation is maintained very well considering its running on a single AAA battery. Do note that the output has a peculiar curve during the first few minutes where it maintains regulation close to maximum output before dropping to about 80% output for the remaining of the battery life.




The Good – Clean design and well-machined body. Regulation is maintained well with good runtime. Compact and light weight.

The Bad – Nothing significant.

The Relative – Beam is clean with a neutral white tint. Uses a twist switch. Is able to tail stand.


Inside outsize image of the 4Sevens Preon ReVO