The Romeo5 and other Sig Electro Optics that have MOTAC (Motion Activated Illumination) are very sensitive to any motion or even vibration.

From Sig Sauer: MOTAC increases battery life by shutting down the system when not in use and instantly activates the system when it senses the slightest vibration or movement. Your sight will be up when you go into action. The ROMEO5 will mount on any platform and the solid aluminum design will give peak performance and years of service.

We have sold thousands of Romeo5 optics and have never seen one that had a defective MOTAC feature. To test the MOTAC feature, turn on the optic and place the optic on a solid surface that has no vibration (a table top, desk, or chair) in a manner in which you can look through and see the dot without having to move or touch the optic. Ensure that there is nothing which might create a vibration and let the optic sit for approximately one minute. The reticle should turn off. You can look through the optic and see that the Romeo5 shuts itself off. If you tap or even slightly move the optic, it will turn back on.

Very slight vibrations, even those from an incandescent light (a customer tested his on the shelf of his safe and an incandescent light was mounted on the underside of the shelf) can prevent the sight from shutting itself off.

Referenced product: SOR52001

Applies to Sig optics featuring MOTAC including most if not all: Romeo1, Romeo3, Romeo4, Romeo5, Romeo6