Understanding Package Naming convention

Hi, I am trying to understand the rhel package naming convention. Eg.

kexec-tools-1.102pre-126.el5_7.7.x86_64.rpm

I understand this is the software package "kexec-tools", software version "1.102", which is a prerelease, package version 126 (the 126th build of the package), for RHEL 5 (el5).
What I don't understand is the "_7.7" part. What does it tell me?

Best,
Isaac