Used for measuring RPM.

Features:

• Compact and easy to store
• It measures 2 ~ 9 blades prop RPM
• It shows 4 digits in a 0 ~ 99,999 RPM range.Multiply the readout by 10 for final rpm reading
• Supplied with a replaceable 3V LITHIUM battery
• Auto shut-off function after five minutes when no signal received
• When the LOW BATTERY icon is on,the battery needs to be replaced
• Display and memorize the maximum RPM value.