A roller for a web-processing machine, the roller having a support core, which is braced in the region of both its ends via a respective bearing arrangement, and an outer covering, which in its axially central region is mounted in a radially fixed manner in relation to the support core and in the region of its two ends is braced in a radially displaceable manner in relation to the support core by a respective additional bearing arrangement, whereby the outer covering is displaceable in the region of its two ends respectively by an actuator arranged within the outer covering, the actuator being adjustable and including two inter-mounted eccentrics to which is assigned respectively one pivoting device, whereby the two pivoting devices are controllable such that the size of the resulting eccentricity and the position of the resulting eccentricity are adjustable preferably separately from each other, the outer covering being non-rotatably connected to the support core.