Meet the Tascam DR-701D: a 6-track field recorder for DSLR cameras with dual built-in omnidirectional microphones and 4 XLR/TRS inputs with phantom power. It has an HDMI input that can be connected to your camera’s HDMI port, allowing you to start, stop recording on both devices at the same time. The device has a rugged design and weighs less than 1.5 lbs. You can use 4 x AA batteries to power it.
The DR-701D has various recording modes. It lets you achieve perfect camera sync with HDMI video clock synchronization. You can use the built-in microphones with external handheld or shotgun mics to capture the surrounding environment. The device is designed with pro filmmakers in mind. More information is available here.