Man I was about ready to throw this thing in the trash the other day I got it from another member a few years ago. I thought I had tried everything to get the thing to read me out some ranges. Until I tried the simplest thing of all I left it under the back seat of my truck and set my tool bucket on the seat. This killed the battery. I put in a new Duracell 9V and wow the ranger finder is working great any time of the day. I felt like such a bone head I should have tried changing out the battery 2 years ago. So for anyone out there using a Leica make sure you change the battery and keep a spare. Just thought you guys should no whos advice your getting and to take it with a grain of salt.