What is the difference between SPP-R210 and SPP-R210C?

Answer

The difference between SPP-R210 and SPP-R210C is Smart Card option.

SPP-R210BKM: Android/Windows bluetooth with MSR

SPP-R210iKM: iOS Bluetooth with MSR

SPP-R210BKC: Android/Windows bluetooth with MSR(Magnetic Stripe Reader)+SCR (Smart Card Reader)

SPP-R210iKC: iOS Bluetooth with MSR + SCR

It depends on the option (MSR or SCR), model name will be different.