Tachmeter for OPE equipment

[mobiledynamics]

What tachmeter do ya'll use to either track hrs or rpm on your small engines.

I use the Works units, but it's a sealed battery.
Just started looking for one with a replaceable battery..

 

[Farmall 1066]

I have used a Stihl tach for 15+ years.

 

[stihlntime]

DTI tech tach or Stihl EDT 8 are both good tachs.