What additional requirement does Article 410 place on adjustable luminaires?

Article 410 emphasizes that adjustable luminaires must be securely mounted and designed to maintain stability when adjusted. This requirement is critical for safety and performance, as an adjustable luminaire that is not securely mounted could pose a hazard by tipping or falling during adjustment, leading to potential injury or damage. The stability during adjustment ensures that when users modify the direction or position of the luminaire, it remains in the intended location without risk of unintentional movement or dislodgment. This design consideration supports both practical operation and compliance with safety standards outlined in the NEC.

The other options like requiring a specific wattage, having a dimming feature, or including color filters are not essential criteria specified by Article 410 for adjustable luminaires. These features may enhance functionality or user experience but do not directly impact the safety and stability focus that Article 410 prioritizes for adjustable luminaires.