The device for stacking sheets arranged to form stacks downstream of a sheet cutting line and comprises an unroller, a printer and a cutter. The T-square has a head with a board edge contact surface and a board face contact surface. Preferably, the clutch is self-regulating, so that the amount of engagement is determined by an amount of water in or at the clutch. , the tetrazole derivative of the formula, thereby improving its absorption rate, and thus can be effectively used to reduce multi-drug resistance in cancer cells. CRM advantageously is applied to conventional WXC node as well as WSS-based WXC nodes in the WDM networks.