A saddle for a sheeting head includes a pair of semi-circular concave edges configured to seal a pair of rollers. The cassette unit 100 comprises a flange portion 111 and a tube member 110 which are welded together, and to the interior of which are fixed a guide member 170, an orifice member 180 and a plate member 166. An input terminal of each of the two comparators are commonly connected together, the other input terminal of the two-input comparator is coupled for receiving a first reference voltage, and a second input terminal of the three-input comparator is coupled for receiving a second reference voltage. For example, an encrypted bitstream that can be decrypted by the security circuit in a first IC will typically not be decrypted by the same security circuit in a second IC, since the physical properties of the two ICs will typically be different. The use of blood-collection bags initially unattached to satellite bags eliminates waste and simplifies the transportation and processing of whole blood.