Description : This is 3D printed prototype with high tolerance +/-0.02, material is SLA ABS like, with a matte finish and smooth surfaces, the whole assembly includes 1 bottom cover and 1 top cover, 2 gears and 1 gear rack, the inner base would move when we push/pull the gear rack, this rapid prototype is in order to test the reliability of mechanical design, but it's not suitable for high strength test.