2.4 but they are engineered poorly and drop out of service and are slow to access.. In several reviews the company apologizes and says they are working on improving them
That was 2 years ago.. I am experiencing the same issues, customer paid over 2600 dollars for system from simple safe.. I am giving it one more day and one
more customer service call, If no improvement I will recommend for them to return to simply-safe for a refund or sue in court for misrepresenting their product.