The STM32F103R4T6A: Runs at 72 MHz with 16 KB of Flash and 6K x 8 of RAM — the entry-level density option in the STM32F103 line.
Peripherals and interfaces — CAN and USB on the same die
The CAN and USB combination is what sets it apart from the lower-end STM32F103 variants — you get both industrial fieldbus and host/device USB on a single 64-pin LQFP. That saves a board-level transceiver or a second MCU in many designs. The 51 I/O lines give enough headroom for a keypad, display, and a few sensors alongside the serial interfaces.
Package and footprint — 64-LQFP
Housed in a 64-LQFP, this is a surface-mount package.