Colour-indicator tyre valve caps

A set of four caps marketed to indicate low tyre pressure through green, yellow or red colour changes.

Listed material: stainless steel.
The source gives 2.4 bar and 36 psi references; these do not establish the vehicle's required pressure or exact indicator threshold.
Listed dimensions: 2.5 × 1 cm.
Supplier claims include standard-valve compatibility and reducing tyre wear or blowouts.
Source image descriptions mention Air Alert Tire Valve blister packaging.

Confirm actual operating threshold, accuracy, sealing and compatibility with the valve and any tyre-pressure monitoring equipment. Universal fit and prevention of tyre failure are not established. These caps are not a verified electronic TPMS replacement. Use the vehicle's specified tyre pressures and check with a suitable gauge; do not rely on colour alone.