Youpin (Xiaomi) Duka 40m LS-P Digital Laser rangefinder

This is a little unit that seems solidly constructed with an aluminium case measuring 86 x 22 x 11 mm. It comes with an attachable lanyard (quite fiddly to get through the hole) and it charges via miniUSB. It only weights 28g.

It has a backlit LCD and two buttons. The button (on the same side as the LCD) starts the laser and the side button changes modes. Unfortunately it's quite complicated to work out the modes as the instruction manual is in Chinese. Units can be set to metres, inches or feet.

The stated maximum distance is 40m and though not fully tested, if it's dark and you can see the dot, it does measure long distances, it can measure continuously as it moves around. It also measures: - 

  • Area
  • Volume
  • Front and Back reference
  • Pythagorean
  • Max and Min
  • One button angles

Though some are relatively easy to work out how to use, without an English manual some of the modes won't make much sense.

The sensitivity does seem to be quite good and it's possible to see the red dot in quite bright outside conditions, though in order to measure the distance of something small, it's likely to be very difficult just in trying to keep the beam steady enough to keep it on the target area. The measurements are accurate to about 2mm.

The main button on the side of the LCD.

Long press turns the ranger on or off.

A 3s press should reset the measuring mode.

A short press will start the measuring mode and another short press will store it (each time).

A 1.5 second press and it will start continuously measuring (the display will show the maximum and minimum measurements).

Clicking the side button will put the device into area measurement (a trapezoid will show on screen), then clicking the top button will measure one side and a second press the 2nd side and an area displayed.

The side button pressed again will put the system into volume mode (a cube is shown on the display) and then the top button pressed for the three measurements.

A third press on the side button will put the unit in Pythagorean mode - a triangle will show (a squared + b squared equals c squared) and pressing to top button will measure a and then b.

A fourth press and a double Pythagorean mode showing a two triangles. Then top button will be a, b and e (the edge and vertices of the triangle and the base c will be calculated).

A 5th press and it's subtracted Pythagorean as above, but c is the base length between the last edge (e) and middle length (b).

The 6th press should put the system in angle mode, so press top button and you measure the base of the triangle, then another press and it will measure the height and calculate the hypotenuse.

There is also a settings mode.

It costs around $16 from your Chinese eCommerce site.