Certified for GMRS obviously, or crystal controlled, or certified for licensed use frequencies as long as they are not also capable of operating in the amateur bands. 95.1761 (c) If wrong, others will surely advise opposite, even if I am correct.
I think the point of not being a jerk and stay within the power limits will avoid any station visit / inspection. Still, Motorola UHF range R2 gear would be okay which is 450-520…if I understand 95.1761 (c) correctly…and one abides the power limits, bandwidth, etc.