Here are some specs for the Evette Alto Saxophone from Buffet Crampon:
Finish: Lacquer
Body/Bell Materials: Yellow brass
Neck Materials: Yellow brass
Sound: Has a distinct break in sound from C2 or C#2 to D2 
The Evette name is used for Buffet's student level instruments, and some of these are stamped "Buffet Evette" and some just "Evette" or "Evette Schaeffer". For the most part, these can be pretty decent instruments, but are still considered student level with pricing to reflect that. 
Here are some insights from reviews: 
Pros 
Ergonomically superb
Outstanding intonation
Horns blow freely across the entire range of the horn
Intonation is even and consistent throughout the horn