A safety device for use in a fall arrest or fall safety system includes an energy absorber to absorb energy in the event of a fall or other impulse event. The energy absorber is a resilient element (such as a tolerance ring) providing an interference fit between a first component of the device and a second component of the device. In the event of a fall arrestor other impulse event, the first and second components effect movement relative to one another, the interference fit being overcome, and the resilient element/tolerance ring acting to resist the relative movement thereby absorbing energy.