Ralph and Gary Greenhoe worked together to design this small brace to gently nestle in between the hand slide tubes near the end crook. The weight is negligible, but the response is astounding. Projection and stability are improved, helping you to create the classic orchestral wall-of-sound brass timbre. For a time the LA Phil trombone section had matching "braced" slides.
I don't know how many sets of these were produced, but know that M/K Drawing do a copy of these but not sure how they compare to these originals.
Three sizes were commercially made to cover the following are available:
Narrow - for small bore trombones with narrow slides: King 2B, 3B, Bach 12, 16, etc.
Medium - for Conn 8H, 88H, 62HI, Getzen Bousfield, Shires T25, T47, Yamaha 882O
Wide - for Bach 42, 50, Conn 62HCL, Getzen 3047, 3062, Edwards, Shires TW47, B62, Yamaha 882OR
I don't know why I bought these, I buy all sorts of old Conn related stuff, so probably thought these would be safe with me as a full set

I was wondering if anyone ever used, or uses these now and if they are they really as effective as claimed.