An unusual communication?We would like to bring to the attention of others a fault in manufacture of an Intersurgical disposable Bain breathing system. Close inspection of the machine end of the system (Fig. 1) revealed a significant communication with the expiratory limb. This defect causes a large increase in the system deadspace and thus would lead to excessive rebreathing when used with normal fresh gas flows. No abnormality is apparent on external examination of the system (Fig. 2); however, the defect caused the system to fail both the inner tube occlusion test (Foex-Crampton Smith manoeuvre) [ 11 and Pethick's test (deflation of a reservoir bag by the Venturi effect of the oxygen flush) [2].Once again this highlights the importance of meticulous pre-operative equipment checks in order to prevent potential harm to patients.