Nitecore Thumb Leo 45lm In-depth review, Pros and Cons

1 x unspecified LED, 1 x unspecified 365nm UV LED
45 lm output
150 cd intensity
integrated Li-Ion battery

The Nitecore Thumb Leo (THUMBLEO) released in 2017. It uses 1 x unspecified LED, 1 x unspecified 365nm UV LED, no reflector and integrated Li-Ion battery. The powerful emitter in this flashlight provides up to 45 lm output, 150 cd intensity, and a beam distance of 24 m.

The Thumb Leo is an impressive flashlight that offers both power and reliability. Its robust build and outstanding illumination make it a versatile lighting instrument. This light has 3 modes of lighting. Without mode memory, this flashlight always starts in the default mode. This USB rechargeable flashlight is designed to be compact and lightweight, making them highly portable and easy to carry.

Nitecore Thumb Leo (THUMBLEO) pictures

Nitecore Thumb Leo / THUMBLEO photo
Nitecore Thumb Leo / THUMBLEO photo
Nitecore Thumb Leo / THUMBLEO photo
Nitecore Thumb Leo / THUMBLEO photo
Nitecore Thumb Leo / THUMBLEO

The specifications below are based on the official data published by the manufacturer, but we also take user reviews into consideration. If you found an error or something lacking in the specifications above for the Nitecore Thumb Leo, then don’t hesite and signal the problem to us.

Nitecore Thumb Leo (THUMBLEO) specifications

NameThumb Leo
Rated 3/5 based on 1201 user votes.

The presence of a flashlight can provide a sense of reassurance and confidence in unfamiliar or potentially dangerous environments.


Weight25 g
Length74 mm
Head diameter24 mm

The 25 g flashlight may not provide the same level of brightness or features as larger models, it can be handy for quick and convenient illumination in emergency situations or for close-range tasks. The length of a flashlight can affect how it feels in your hand and how you can grip and maneuver it. A longer flashlight may provide a more substantial grip, making it easier to hold and control, especially if you have larger hands. This flashlight features a captivating black color.


Emitter1 x unspecified LED, 1 x unspecified 365nm UV LED
Color temperature6500 K
Switchelectronic side

The choice of color temperature depends on the specific lighting application and personal preferences. The Thumb Leo has electronic switch. Some flashlights with electronic switches have programmable features that allow users to customize the behavior of the flashlight. This may include setting specific modes, configuring brightness levels, or enabling unique functions according to individual preferences.


Flux45 lm
Intensity150 cd
Throw24 m
CD/LM factor3.33

If you mainly need a flashlight for basic tasks like finding keys, navigating in dimly lit areas, or occasional use around the house, 45 lm can be adequate. 150 cd can provide a reasonable level of luminous intensity for many everyday lighting tasks. The throw distance refers to the maximum distance at which the flashlight can effectively illuminate an object or target. The stated throw distance typically indicates the point at which the brightness falls below a specified threshold, such as 0.25 lux. Flashlights with a higher cd/lm ratio typically excel in long-range throw and focused beam applications, while flashlights with a lower cd/lm ratio may provide a wider and more evenly distributed beam for closer-range illumination or general-purpose use.


Modes3 modes
Mode memoryno
Ramping modeno

Modes on a flashlight refer to different output settings or levels of brightness that can be selected to suit different needs and preferences. SOS mode of the Thumb Leo produces a specific sequence of long and short flashes to signal distress or emergency situations. It is commonly used in outdoor adventures or survival scenarios.


Batteryintegrated Li-Ion battery
Battery indicatoryes
Charger portmicroUSB
Thermal regulationno
Impact resistance1 m
SpecialsUV light
adjustable head
red/blue light

The Thumb Leo flashlight utilizes integrated Li-Ion battery as its power source. The Thumb Leo has a battery indicator. A battery indicator is a feature that provides information about the remaining power level of the flashlight's battery. It helps users monitor the battery status and estimate how much runtime they have left before the battery needs to be recharged or replaced. USB rechargeable flashlights have become increasingly popular in recent years due to their convenience and sustainability.

The Thumb Leo flashlight doesn't have built-in LVP, it is recommended to use a protected battery to prevent over-discharging. The protective circuit of battery helps safeguard the battery from various potential risks and ensures safe and reliable operation. This flashlight doesn't have built-in temperature control. Flashlights without thermal protection may rely on other design elements for heat dissipation, such as heat sinks, fins, or body materials with good thermal conductivity.

The Thumb Leo flashlight with IPx8 rating can withstand being submerged in water beyond 1 meter for a prolonged period, typically specified by the manufacturer. This flashlight is designed to withstand impacts of up to 1 m without sustaining significant damage, ensuring its durability and reliability even in challenging conditions. Auxiliary LEDs with different color options or specialized modes can be beneficial for specific tasks. UV light of Thumb Leo can reveal the presence of urine or other stains left by pets on carpets, furniture, or other surfaces.


Package contentskeyring

The performance of the Nitecore Thumb Leo flashlight is measured according to the ANSI / NEMA FL1 Standard 30 seconds after switching the light on. The ANSI/NEMA FL1 2009 Standard is a set of flashlight performance guidelines.

Nitecore Thumb Leo (THUMBLEO) comparisons

According to our statistics, the Nitecore Thumb Leo flashlight was most often compared on our site with the following flashlights.

Nitecore EC4S (EC4S) Nitecore EC4S Nitecore P23i (P23I) Nitecore P23i Nitecore P30 (P30) Nitecore P30 Nitecore MH12GT (MH12GT) Nitecore MH12GT Nitecore P10i (P10I) Nitecore P10i Nitecore P20 v2 (P20V2) Nitecore P20 v2 Nitecore Tube V2.0 (TUBEV2) Nitecore Tube V2.0 Nitecore Tini 2 (TINI2) Nitecore Tini 2

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