He'd used an old-fashioned mechanical key, as well, and the colonel shrugged.

A wide range of credentials can be used to replace mechanical keys.

It was rectangular and flat, small enough to hold in a hand, but larger than any mechanical key.

Jackson tried first the electronic one, then the mechanical key.

Keycards are frequently used in hotels as an alternative to mechanical keys.

Mark bent down and released Greg's legs with a complex-looking mechanical key.

Before departure, two mechanical keys of ten bits each were inserted into the shown reader.

She produced four sets of handcuffs: the old-fashioned kind, with a mechanical key.

It had a simple mechanical key which Slade clicked home as he stood.

But Mercedes isn't taking any chances with the traditional mechanical key and is moving to a keyless system.