Yanagisawa 65 Brass Tenor Saxophone Neck
I found the tone on this crook a lot fuller and more open than the 64. It seemed similar to the standard 991 crook, but with a tad more breadth to the tone for my money. It also produced a very expansive sub-tone. Very nice stuff!
In terms of fitting these crooks on other saxes, I found that they slot nicely on to the Yamaha 62 and Custom models, but I found them to be very loose on all Selmer and Keilwerth saxophones