The Dynalco SPD-100 Signal-Powered Digital Tachometer is a solid-state tachometer that features a 4-digit, unlighted LCD display with gate time range of 0.26 to 5.70 seconds, field- programmable. This well-sealed signal-powered tachometer is designed for rugged indoor and outdoor applications.

The Dynalco SPD100L Signal-Powered Digital Tachometer is a solid-state digital tachometer gauge that features a 4-digit, lighted LCD display  with gate time range of 0.13 to 2.85 seconds field-programmable. This intrinsically safe tachometer is well sealed and designed for rugged indoor and outdoor applications.

The MTH-103E is a newer version of the MTH-103D. The function, package size and wiring are the same although the MTH-103E has a keypad that replaces the old push button, making programming easier and quicker.