Fast, durable colorimetric breath indicators for visualizing exhaled CO₂ to assist in verifying proper intubation. StatCO₂ (for patients over 33 lb), Mini StatCO₂ (for patients between 2 lb and 32 lb), and Neo-StatCO₂ (for patients between 1/2 lb and 13 lb) are designed to connect between an endotracheal tube and a breathing device. Patient’s exhalation gas is led through the indicator to detect approximate ranges of end-tidal CO₂ by color comparison assisting in verifying proper tube placement. StatCO₂ and Mini StatCO₂ have pull tabs to activate device, but Neo-StatCO₂ does not.