She has several features to make her proud: 1-She's the first 10 strings with a Port Orford Cedar top built Using 1943 Hauser Engineering. 2-She´s also the first  10 strings 640mm  on the planet and she is definitely the most affordable 10-strings concert you'll EVER find... 
She produces a fantastic sound full of harmonics and you feel as though a string quartet was accompanying you ... such is the amount of sound and reverb you get from the extra 4 vibrating strings. I was taken to that magic Las Rosas day in an instant... just as the first notes were plucked... What a beauty. Adapting to a 10-strings requires a few hours and even if your intention is to play your " standard repertoire" you'll find that playing it on this babe will take it to a totally new and SUPERIOR level....
As with all Bellucci guitars, I had to include unique artistic details...in the luxury French marquetry and splendid Red roses rosette. The double truss rod  Walnut reinforcement are only some of the exquisiteness of this MASTERPIECE. 
 

640mm or 650 mm

Radiused or flat fingerboard?

Regarding 650mm or 640 mm guitar construction, keep the following rule at hand: If the distance between the tip of your thumb and the tip of your little finger is equal or less than 9 in. when fully stretched, use 640 mm. Adapting from one scale to the other takes no time at all.

Radiused or flat fingerboard?
The radiused fingerboard has been around the acoustic and the electric guitar since day one. The same is true for most instruments of the Stringed family of instruments (violas, violins cellos, bass). Radiusing (image above) makes barre and left hand stopping A LOT easier. The only drawback is that you will NEVER want to play a  flat fingerboard after that.