USB to I²C/UART/FT1248 Breakout Modules, FTDI Chip Versions Available
(757-0054) UMFT201XB-01 - FT201XQ Breakout Board
(757-0067) UMFT230XB-01 - FT230XQ Breakout Board

This range of FTDI breakout boards are designed to convert USB to serial or parallel interfaces. The UMFT201XB-01 (757-0054) bridges USB to I²C and the UMFT230XB-01 (757-0067) bridges from USB to a UART IC.
Does it house a USB connector?
No these breakout modules do not have a USB connector on-board. Instead, the module plugs directing into a USB socket and the contacts on the PCB meet the contacts within the USB socket.

What voltage do they operate at?
The UMFT201XB-01/UMFT230XB-01 operate at 3.3V. However, all I/Os are tolerant to 5V.

How big is it?
These breakout boards measure 45.5 x 14.95 x 5.2 mm