Compliance is the most critical factor in this category. Ensure the machines carry CE, RoHS, and FCC certifications for electronic safety. For specific markets like the US or Europe, check for GLI (Gaming Laboratories International) certification, which validates the fairness of the RNG (Random Number Generator) algorithms. Technical specs should include dual-screen support, touchscreen functionality (Capacitive vs. Infrared), and customizable RTP (Return to Player) percentages ranging from 60% to 99% to meet local gaming regulations.