When evaluating dental units, prioritize high-quality motor systems (such as Linak or Timotion) for smooth, noise-free chair movement. Ensure the unit features durable PU or fiber leather upholstery for patient comfort and easy disinfection. Key technical components should include a rotatable ceramic cuspidor, LED sensor operation lights with adjustable color temperatures, and a multifunctional foot controller. For the water system, verify the presence of an independent clean water supply system and high-quality imported air and water tubes to prevent leakage and aging.