This is version II of the a7s. It has a Full-frame sensor, Captures 4K video, plus Full HD up to 120fps.
The original a7s is regarded one of the best cameras on the market for video capture. Version II adds internal 4k video capture, increased dynamic range thanks to the Slog3Cine setting, impressively clean low-light images with noise-free shadows, and image stabilization built into the camera so it works with all lenses. The Exmor CMOS sensor and the BIONZ X image processor are well known for producing high quality video and still images with high dynamic range, low noise, and ISO sensitivity all the way up to 409600. One of the best got better. This is the Sony camera to get if you're shooting video. Higher resolution sensors are forced to skip lines to scale down to the necessary resolution for video, which contributes to undesirable effects like aliasing and moire. Since this camera's sensor does not skip lines, it produces very high quality video.

• 4K video capture at 3830x2160p video at 24/25/30 fps
• Full HD video capture at 1920x1080p video at 24/25/30/60/120 fps
• HD video capture 1280x720p video at 25/30 fps
• Clean HDMI out for external 4K video recording
• Sony E-mount lens mount
• 3.0" 1222K-Dot tilting LCD monitor
• 169-point contrast detection auto-focus system
• Electronic 2359K-dot viewfinder
• ISO 50-409600
• Hot Shoe
• 3.5mm microphone input jack and a 3.5mm headphone jack
• Built-in Wi-Fi
• 1 SD card slot accepts SD/SDHC/SDXC media cards
• 1 Memory Stick slot accepts PRO Duo/ PRO HG-Duo / XC-HG Duo memory sticks

• Body cap
• Strap
• 2 Batteries
• Battery charger
• Camera bag

Click here to download the a7SII user manual .pdf from Sony's documentation website