A roller shutter comprising a shutter moveable between a retracted position and an extended position is described. The shutter comprises one or more laths wherein the one or more laths comprise first and second surfaces mechanically connected by first and second sides and one or more internal supports. The one or more internal supports are configured to collapse preferentially with respect to the first and second sides. The presence of the one or more internal supports provides the laths with increased mechanical strength. However, by configuring the internal supports to collapse preferentially with respect to the first and second sides provides a means for absorbing and dissipating this force through the shutter. The roller shutter finds particular application as a horizontal shutter within heavy industry environments.