A clip for clamping an object has a clip body where a pair of clip members are pivotally connected to each other, clamping force increasing members for increasing a clamping force of the clip body; and fixing means for supporting the clamping force increasing members on the clip body. The callback server monitors terminals that have such flags set and is arranged to transmit an alert to the calling party when the called party next becomes available. The signal from the seismic detection circuitry is converted into a digital signal, which is then relayed to the data recorder. The first and second cleaning rollers are height-adjustably arranged in the housing such that an adjusting device acts on the first and second cleaning rollers and moves them into a working position or into a parking position, respectively.