Apple has released the second public beta for OS X El Capitan 10.11.5. Members of Apple's Beta Software Program can grab it now from the Updates section of the Mac App Store.

Apple released OS X 10.11.5 Public Beta 2 to testers

This comes on the heels of the release of the second 10.11.5 developer beta. It's not known at this time what changes will come with OS X 10.11.5 when it launches publicly. It will likely feature a number of bug fixes and performance improvements.