When you have several automatic winding watches - watch winder is a must. It is not just a "comfortable garage" for your mechanical watches, but a tool that keeps parts moving and oil up in the jewel cups, prolonging the time between the cleanings. The watches will always be set to the right time and date; some very complicated calendar models can take 15-30 minutes to have reset properly. Lastly, watches with screw-down crowns don`t have to be unscrewed as often, thus shortening the thread life of tube and crown.