This book describes the collection of 55 locks and keys of the Holy Ka'ba preserved at Topkapı Museum in Istanbul.

The book consists of two parts. The first part gives information on the history of the collection the shape and the mechanism of the locks and keys the materials used in manufacturing the manufacturer if known the motifs and inscriptions carved on the locks.

The second part describes each of the locks and keys in chronological order according to the Abbasid Mamluk and Ottoman periods.