This is a half-bridge load sensor, which is widely used in weight scales. When the half-bridge is being stretched, it sends signal via the red signal wire. You can use multiple load sensors simultaneously to increase the capacity range.
This module uses the newest 2.4GHz transceiver from Nordic Semiconductor, the nRF24L01+.This transceiver IC operates in the 2.4GHz band and has many new features! Take all the coolness of the nRF2401+ and add some extra pipelines, buffers, and an auto-retransmit feature.