iwc DA VINCI CHRONOGRAPH Mode D'emploi page 27

Servicing your Da Vinci Chronograph 24 | 25
Although the parts in this watch are all manufactured from top-quality
materials, a number of components are subject to natural wear and tear. It
is particularly important to ensure that the points at which wear occurs are
always well-lubricated and that oil contaminated by metal abrasion is
regularly removed. For this reason, we recommend that you have your
watch serviced approximately every five years. Please contact an
authorised IWC Official Agent or send your watch directly to the IWC
Customer Service Department in Schaffhausen.
Effective from January 2009.
Technical specifications subject to change.