Home NS Vas stem, the first of its kind! 30 Nov 2021 New Powerbox SC alloy is ready! The Powerbox SC Pod power-meter is the next step in FSA’s power-meter offering. With an accuracy of less than 1%, it features virtual L/R balance to estimate total power more accurately it is Zwift compatible via BLE5.0 and has a 450H battery life (single CR2450).