Product: Camco 25553 Precision Curved Ball Levels
Overall sentiment: negative
Customer reviews:
I installed these with ease, then raised my RV up about 5 degrees and it didn't even register, lowered the RV, didn't change.  These seem like a great concept, but the word precision in the title is an outright lie.  Plus/Minus 5 degree accuracy is more like it.  When the RV is visibly not level and the ball still says ZERO, you shake your head and say WORTHLESS 
 Borke withing 2 days of use.. 
 Doesn't seem to work as well as the liquid filled levels. 
 They are junk! very poor excuse for a level. I should have sent them back without installing them, One fell apart one first trip of 50 miles. 
 They don't work very well. 
 Not very good, my 12" level is better 
 These are mounted level on my trailer, but the ball does not roll smoothly enough to detect changes in adjustments while raising/lowering the main jack stands on my 5th.  Just too much internal friction, I guess.  I highly recommend using one of the fluid-filled designs instead.  These ones are going in the garbage. 
 Don't stick to great. Lost one already . Don't trust the tape. 
 Okay 
 Not worth the money, stick to bubble levels. Not a precision level, it has a small dent at the zero mark that keeps the ball from moving
properly. 
 This item arrived quick and in good shape.  They were easy to install. BUT.... do not trust the tape adhesive on the back. On the first trip one of them fell off. I have removed the other one and re-installed it with gorilla glue. 
 Although these level were a value, once installed on my camper, they don't really work very well.  The steel ball does not roll freely which affects the accuracy of the leveling process. 
 These balls are not worth a damn.  You can tilt your camper A LOT and they won't move at all.  Save your money and get the bubble style instead. 
 You would have to be so far off that items would roll of of your counter before these would be handy. Don't use them at all anymore. 
 Very inaccurate and will read level until you really tip them. They also get stuck in place and you have to tap them to get the ball moving. The adhesive is useless and when I went to screw them in they cracked under the lightest pressure. If they weren't so cheap, I would take the time to send them back. Now they are just headed for the trash and I have two holes in my trailer for nothing. :( 
 The balls inside do not quickly adjust to small degrees of change. Have to tap outside to try & get to move. Will be replacing with liquid bubble type.