This is a one revolution, metric dial indicator. It offers you the following benefits: 

• Bezel clamp and lifting lever (optional) can be attached to either right or left side. They can be easily installed and removed without tools. 
• No through screw holes on the frame and secure adhesion between the bezel and the crystal as well as the use of an O-ring prevents water or oil penetration. 
• It eliminates the possibility of reading errors due to miscounting multiple revolutions.