Why would you ever futz around with a bubble level when you can find a straight line with a LASER? <Inception horn>
DEWALT’s self-leveling cross-line laser mounts to any wall, and projects a perfectly straight horizontal and vertical line in either direction for up to 165 feet. It’s currently listed on Amazon for $143, and its all-time low is $130. Today only though, it’s included in an $89 bundle with a few handy accessories. Needless to say, that’s the best deal ever on this thing, and it’s likely to sell out before the end of the day.