asuswrt-merlin
on SourceForge
RT-AC5300/Release/RT-AC5300_384.5_0.zip
RT-AC3100/Release/RT-AC3100_384.5_0.zip
RT-AC3200/Release/RT-AC3200_384.5_0.zip
RT-AC88U/Release/RT-AC88U_384.5_0.zip
RT-AC87U/Release/RT-AC87U_384.5_0.zip
RT-AC68U/Release/RT-AC68U_384.5_0.zip