The Go Direct® Acceleration Sensor (GDX-ACC) is sized to fit inside some rocket tubes.

The Centuri Standard Tube ST-11 and the Estes Body Tube BT-55 are the smallest body tubes that will hold the Go Direct Acceleration. The sensor can be placed in a larger tube, but you will want an engine mount with inner diameter sized to hold 1.13 in or 28.7 mm diameter motor.