Product: Camco 25553 Precision Curved Ball Levels
Overall sentiment: positive
Customer reviews:
We use these levels in our pop up camper, they work pretty good, they aren't hugely accurate, which is fine for our purposes.  However 'Precision' is a stretch.  The sticky backing isn't great, one of the levels fell of the internal wall of our camper the first weekend. 
 all good 
 Best ones I've found for my truck camper... have six of them, two front corners, two front sides and two rear corners! 
 Gets the job done. 
 These work well. 
 WORKS WELL 
 Worked as described 
 good quality levels and great price 
 Very easy to install,easy to read with the ball level inside. Like it better than the bubble levels. 
 Nice 
 OK, but inside got a little cloudy in a short period of time. 
 Good product for price works well would buy again if needed, bought this to put in camper easy way to make sure it is level 
 Had to send the first set back as there was a nick inside that would hold up the ball which isn't what you want in a level.  The new ones work fine. Are more precision than alot of bubbles. The trick is making sure your R.V. is perfectly level when you install these.