Cleaning a rangefinder helps to retain the quality and also prolongs its life. Here are some essential cleaning tips:
Take out the removable parts like batteries, SD cards, rubber-parts, etc. Get a soft piece of cloth (microfiber fabric) and a contact lens solution.
Wipe away all the dust and sand particles from the rangefinder. Put some cleaning solution on a cloth and rub gently around it.
For the final step, dry the rangefinder naturally before setting the battery and SD card in their places.