I have be use the powerblock system for 12 year ... . . I be a 63 year old special force Vietnam Vet ... . . I also hold a personal training certification from ace ... ... I have be trainng and body building for over 40 year ... ... and I can tell you that the powerblock system be the finest dumbell system i have ever use ... . I use mine 3-4 time a week ... I get a excellent workout , that help I stay very fit ... ... and i must tell you i like the feel of the product as well as the sturdiness ... of the block ... of course you have to be careful as you would with any heavy weight set ... just use common sense and keep training ... I would not use another brand and I reccomend they highly