the intumescent material 5 of the firestop collar thus expands not only radially but also axially inwards that is to say parallel to the longitudinal axis a of the pipe 1 that might have been destroyed by the fire the firestop collar 4 is for example a fabric collar however it is likewise possible to employ other firestop collars 4 such as for instance a firestop strip or a firestop bandage which are soft and flexible enough to be deformed by the intumescence pressure caused by the expansion element 26 in an alternative embodiment the second leg 23 of the anchoring element 20 can be provided u2014 on its flat side that is in contact with the flat side of the expansion element 26 situated opposite from the firestop collar u2014 with optional fastening means 38 shown schematically such as for instance mandrels or hooks and the like which secure the expansion element 26 the fastening means can also be arranged on the side edge of the second leg 24 and can be configured for example in the form of hooks that are facing the expansion element 26 in order to be able to build up sufficient intumescence pressure it is advantageous if the device 10 according to another embodiment has a shell formed by the anchoring element 20 with the expansion element 26 being arranged in the shell fig3 shows such a device 10 in a simplified perspective view for purposes of fastening the device to a wall or floor ceiling the first leg 22 of the anchoring element 20 is provided with preferably stamped fastening openings 36 the device 10 can preferably be stamped out.