The 315MHz 433MHZRF link kit is consisted of transmitter and receiver, popularly used for remote control.
The popular link is like this: MCU -> Encoder -> Transmitter ------ Receiver -> Decoder -> MCU
PT2272(Encoder) and PT2262(Decoder) are optional, their existence is to
1)avoid confusing when multiple RF links in range
2) isolate disturbance.
You can integrate the encoding and decoding work to the MCUs on both side. Whenever there is no 433Mhz devices around, you may use it as direct cable connection.