The Treadmill with Vibration Isolation Stabilization System, commonly abbreviated as TVIS, is a treadmill for use on board the International Space Station and is designed to allow astronauts to run without vibrating delicate microgravity science experiments in adjacent labs. International Space Station treadmills, not necessarily described here, have included the original treadmill, the original TVIS, the БД-2, the Combined Operational Load-Bearing External Resistance Treadmill (COLBERT), and the Treadmill 2 (abbreviated as T2). Some share a name, some a design, some a function, some use different (passive) vibration-suppression systems, some it is unclear how they differ.