The bumps on the side of these cylinders are grip deflectors and make it more difficult to pull the cylinder out of the door once installed. You will need to remove the door handles to fit these cylinders as the grip deflector will prevent the cylinder sliding through the door handle opening. This will just be a case of unscrewing the door handles, placing the cylinder through the larger opening on the door itself and then re-attaching the handles over the cylinder. 
Most cylinders do not have these as pulling a cylinder out of a door is already a difficult task in itself due to it being held in with a screw to the side.
In some cases these can get in the way as some doors have a tighter space for the cylinder. In this case we would recommend using a metal file to remove the grip deflectors.
The grip deflectors are not essential and this will not affect the operation of the lock in any other way. All other security features will remain intact. 
Alternatively, if you do not wish to do this then the cylinder will not be suitable and an alternative without grip deflectors will need to be used.