Teradek's Cube-105 HD-SDI Encoder is the same as Cube-155 except that the 155 additionally features WiFi and an internal battery. If you don't require these, then you can take advantage of the 105's more affordable price.
The 105 connects to a camera by SDI, encodes video and embedded audio, and streams these in H.264, in up to 1080p/30, to an optional decoder or to a designated URL, streaming by Ethernet or optionally by a 3G/4G USB modem, which connects into the 105's USB port. You can at the same time also store proxy files to a MicroSD card or stream them to a computer over a network. (You would need to first enable a feature called "Proxy Recording" for free from a Teradek forum.)
Cube can be used camera-top, attaching right into a camera's hot-shoe, or you can mount it onto a rig by an included 1/4" mounting screw. For power, you can use the included AC adapter or you can connect a compatible 2-pin Lemo battery, namely, Teradek's Canon BP-945, Panasonic D54, and Panasonic VW-VGB6. These batteries are sold separately.
Streams video and embedded audio in up to 1080p/30 in H.264 to an optional decoder or designated URL
Can simultaneously also save or stream proxy files
Streams by Ethernet or by an optional 3G/4G USB modem
Stores to an optional 32GB MicroSD card
Attaches to a camera's hot-shoe or onto a rig by a 1/4"-20 screw
An OLED screen indicates battery life, online status, and the URL being streamed to