What can I say, it feels like 20lbs with a durable rubber outer shell. I let some air out to get almost no bounce. I am very happy I didn't try to go the DIY route as this is so much nicer and a killer workout. I throw it and then run to it over and over, use it as a salm ball, Russian twists, and wall balls.
Have only been using the ball for 2 weeks, but so far it seems to meet expectations. I was worried that for such a cheap price the quality might not be top notch, but everything seems great. Quality seems just as good as the one selling for $** at a local brick and mortar store.
This ball can withstand a few heavy workouts. It gets slippery though, so that's something to watch out for, which is why I say the quality is good (as compared to Muscle Driver). However, the price for this product can't be beat and this is an excellent addition to have in a home gym.
So far so good with this 'No Bounce' Slam Ball. Great for indoors as well as out. I have the 20# & it is challenging when used in a Tabata type workout. Another great fitness tool to use in the arsenal! If you're looking for a training tool w/ multi use: slams, abs.... This is it w/ great quality & price.