Fast, no lag! 2nd SIM uses 3G/LTE and 2G will be obsolete here in Canada end of 2018. Unfortunately I revived a phone that didn't take a charge unless it was turned off. I had to fight to get an RMS from a 2nd market seller. $55.00 CDN to return to China a $210.00 CDN phone. I will not buy a THL phone again, my THL 5000 that isn't even 1½ years old I can't get a battery delivered here. Not worth the money if you are here in Canada, poor value for no parts availability.