Negrini and Camimari are compatible with each other, similar to LP and LP knock-offs. The Negrini is slightly longer, but they will fit in each others socket. Since the new FIE 2-prong rule, Carmimari hasn't been used, but before that at Worlds and Olympics that would be the only connector. I was talking to an Italian Armorer and he said if a fencer brings anything, but a Carmimari for Foil/Sabre, the connector is 'accidentally' cut off and replaced and the guard connector is lost also. And as I said before, non-Italian pommels & tips are lost also. I have them on my Foils, but since I haven't fenced since Sabre went electric, it has been a few years.