SK****2, SK*****8,SK*****6,SK*****2 support *2 calls at one
time,which is different in the number of SIM cards it can insert.
SK****2 can insert *2 SIMs while SK*****8 can insert **8 SIMs at
most,means 4 SIMs in one channel.SK*****6 can insert **6 SIMs at
most,means 8 SIMs in one channel. Similarly, SK*****2 support *6
SIMs for each channel.
