and Gamo copies. They won't replace a Diana trigger.
For $10 or so you can get a little kit that uses your stock Gamo blade but accomplishes the same as the "GRT III."
I got one from Rich from Mich:
http://home.comcast.net/~peterdragin/index.html/default.htm
They are also available from PSP
http://home.joimail.com/~sifu_mcconahy/index.html
Or you can make your own.
Hope that helps,
--
Dan (in NY)