Update: I just had l.explication by service Jabra. His answer
"The second generation has a new wireless technology called NFC or communication field proche.C'est written about boite.L'une other differences too, is that the second generation comes in a cardboard box while the first in a box plastique.J'espère that these information can help you.
Do not hesitate to contact us again for more information about our products.
Thank you for contacting Jabra Customer Service, Europe.
Sincerely, "
The item sold on Amazon specifies that the enclosure is compatible nfc which is totally false. Very very bad point for Amazon !! Limit deceptive sales
Concluded: finally, I returned to the enclosure Amazon and took instead the mini Bose soundlink. Certainly more expensive (50 euros more) but nothing in sound. Having tried 2, the Bose speaker is far ahead in the Solemate sound quality. The Solemate happened quite quickly saturated. Nothing like the Bose offers a sound volume and an incredible dynamism.