It has an elevation of 3,333 metres (10,935 ft) above sea level.

The new name was chosen to honour Germain Sommeiller, the civil engineer which directed the construction of the Fréjus Rail Tunnel between Savoy and Piedmont.

[3] In the French subdivision of western Alps it belongs to the Massif du Mont-Cenis while in the SOIUSA (International Standardized Mountain Subdivision of the Alps) it is part of the mountain group called "gruppo d'Ambin" (Italian) or "groupe d'Ambin" (French).

A geodetic point of the Italian Military Geographic Institute is defined on the top of the mountain.

The easiest route for the summit starts from passo Settentrionale dei Fourneaux (3,159 m, which connects Exilles and Bardonecchia), then follows the south ridge of the mountain.