This is a D flip flop, and it is a one wide modular design (you can place another one right next to it) that is extremely compacted.

If you're wondering what the hell a D flip flop is, its a simple circuit similar to an RS NOR latch. There is an input, which will not affect the output, but once the refresh button is hit, the output is "saved" to the current input.

This is a great tool for constructing compact ram; however, the design is designed to be small not fast. If you would like to speed the ram up a bit, put an extra space in between each flip flop and replace the repeaters with wire. The extra gap will allow the wires to not interfere with each other. That version is less compact, but less repeaters means more speed.

Have fun and enjoy! :)