Bought this hammer for climbing training (pronation and supination). It's cheap and that's the only good thing about this hammer, even for my main purpose. I can't say anything about durability as I only keep it next to my desk, but it smells like chemicals. The gassing is strong and the smell lingers in the hand for several hours. Even after cleaning, sunbathing, and all the other tricks you use to get rid of that awful vinyl release, it still stinks. Even after wrapping it in sports tape to keep my hands from smelling, it still stinks, and so do my hands. Whatever inferior materials they use in this hammer still seem pretty volatile and I wouldn't recommend anyone touching this thing. It's not good for work, it's not good for exercise, it's not even good for a doorstop because it still smells like poison. Update 02/01/2021: This item still smells as strong as the day I bought it. I just took it and took it to another place and my palm smells after holding it for 10 seconds. I came looking for other weights and sleds and decided to see if my hammer had improved at all. It's not like this. Very strange plastic they used.