value of 1000 leaflets whereupon the unit 10 communicates with the finishing machine to halt processing the counted product is easily identifiable as constituting ten distinct batches by the offset leaflets the life count memory runs alongside the batch count memory and job count memory for keeping a lifetime total of increments recorded by the unit 10 this enables periodic maintenance to be carried out after a given number of u2018 counts u2019 for example 50 000 increments in this embodiment the control circuit 36 is programmed to display a message of the lcd portion 12 to call a maintenance engineer the unit 10 also includes a variable count mode for example for use as a calibration tool for checking that circuitry 30 and or the means of interrupt used with the unit 10 is functioning correctly fig7 shows a flow diagram for a portion of this variable count mode and will be described by way of example with reference to a pre programmed calibration test the calibration test is set to count a total number of 1000 leaflets wherein the first 200 leaflets have a kick or batch indication per 50 leaflets with a dwell time of 0 5 seconds the next 500 leaflets have a kick or batch indication per 100 leaflets with a dwell.