"Patek Philippe Service Manual and Practical Guide
concerning the modifications made to the different calibres for the use of watch repairers"

Calibre B21, chapters include

* Calibres for ladies watches
* Claire's for mens watches
* Calibres with automatic winding
* Pocket watch calibres
* Perpetual calendar
* Shock absorber systems
* Spring checking and adjustment
* Lubrication table
* Small clocks

Back pages reads' Printed in Switzerland - Haefeli - 600/ 71'
Size 32 x 25cm