I purchased this to level a 60ft x 12ft technology sled. Unfortunately I bought it months before I really needed it. When I started, the laser was pretty good to see in daylight. After about 30 minutes I noticed that the laser was noticeably dimming. I replaced the battery. It wasn't making things any better, so I turned it off, thinking it might need to cool down. When I turned it back on it got a little brighter, so I kept using it, although it quickly dimmed back to where it was before. I ended up having to end up with a red laser level that I've been using for 18 years. You might be luckier than me, but next time I'll spend more money.