A switchable rocker arm

A rocker arm comprises a first roller for engaging a first rotatable cam surface whereby at least part of the rocker arm can be pivoted by at least the first rotatable cam surface to move a valve to cause a first valve event, and a further roller for engaging a further rotatable cam surface whereby at least part of the rocker arm can be pivoted by the further rotatable cam surface to move the valve to cause a second valve event which is different from the first valve event. The rocker arm is configurable in a first mode of operation in which one of the first and second valve events occur and a second mode of operation in which both the first and second valve events occur or the other of the first and second valve events occur.