Extra-large coverage and a superb example of the Swiss mapmaker's art.
This map, together with Mont Blanc - Grand Combin (5003), cover the Haute Route from Chamonix to Zermatt and beyond. This one actually covers from Mont Collon to Simplon.
1:50000.
NB. These maps do not show ski routes. It is possible to get 1:50000 special ski route maps of the Swiss Alps, but each map is quite expensive and it takes five to cover the Haute Route.