| 摘要 |
Fastener (1) having a driving head (2) which includes at least two superimposed non-circular recesses (3, 4, 5) for receiving the bit of a driver (7) with which driver a torque can be applied to operate the fastener (1), characterised in that the fastener (1) comprises a security feature whereby said torque needs to the applied to at least two of said recesses (3, 4, 5) in order to operate the fastener (1). |
