Mitchell mechanical recording tachometers are specified accurately to within 25 RPM over the range of 1000 to 3000 RPM. Range marking material included. 2-1/4 inch Mechanical Recording,  FAA-TSO Approved.
Part Number RPM
D1-112-5223 2300 RPM
D1-112-5224 2400 RPM
D1-112-5225 2566 RPM
D1-112-5240 Special-Rotax 914