Features:

• Valeo 55 Centimeter Body Ball comes with a wall chart illustrating a step-by-step exercise program and a high-volume air pump
• 55-centimeter model is the optimum size for users 4-feet, 11-inches to 5-feet, 3-inches tall
• Ball provides a low-impact and highly effective method for strengthening your core abdominal and lower back muscles
• Ball offers a wide range of functions: desk chair, training ball, and baby bouncer
• Sturdy rubber ball cleans easily and is stable for exercises

This 55cm ball was a good size (I'm 5'3") though it's unfortunate you can't choose the color (it came in a pearly white). The pump is easy to use but takes a while, slips often, and makes an annoying squeaking sound. Also it's made of cheap plastic, and ripped along a top edge eventually. Was repairable with a piece of tape though.

Unfortunately, after a few short months of use as a chair, the ball developed a tiny leak and stopped doing, well, its duty of being an inflated ball. One day in a particularly bored state, I found the leak, covered it, and pumped it up several times, but somehow it always deflated. I wish my $12 had lasted a bit longer.

Function:
I mostly use this as a chair, though this involves putting more regular pressure on it than most people buying for exercise, so I think that's a good test of its resilience. I've had no problems after a couple months. The pump works fine and is easy enough to use.

Smell:
It smells strongly when you first unpackage it, but once you leave it pumped up for a few days, that goes away completely. Don't try to wash it off like some reviewers--it's not going to give you cancer, and washing it will probably reduce its durability, because that smell probably comes from a coating that the ball absorbs when it expands (I don't have a strong chemistry background, so I'm just speculating, but it makes enough sense).

I received the Valeo Body Ball today and started to inflate it using the included pump and measuring tape. The pump was a pain to use and kept slipping. It took me about a half hour to inflate to 58 cm (it is a 65cm ball). I decided to under inflate it because I am only 5'4 and therefore on the small side to use this size ball.

I used the included plug and left the ball sitting in a corner UNUSED for about ten minutes. All of a sudden, there was a giant WHOOSH of air, my dog freaks out, and I look over my shoulder and the ball has burst. It burst cleanly down the middle. I am very upset and will try to return it. I never sat on it or used it in any way. It was sitting on carpet. Worst product EVER.

This ball took me 5 minutes to inflate using an ELECTRIC pump. You could never inflate it with the pump provided. In addition, the ball is "sticky" compared to other balls I have used in the gym I frequent. I bought this because the price was low. If I were you, I would pay more for a better ball.

Got one of these for stretching and to use with workouts. It was $5 at Marshalls so I bought it. I'm on the short side, so the 55cm was actually a good fit for me.

With the "tape measure" ring it was easy to get it to the correct inflation size. Bad news, however was that the pump failed on me after only partial inflation. Lucky thing I own a multi-use hand pump (for bikes, balls, etc.) and rigged the cap to work.

The ball itself is very high quality, like those you find at your local gym. Hasn't popped or had any leaks on mine yet (previous Everlast ball leaked). So if you need a good affordable stability ball and own a hand pump (just in case), give these a try.