We reported the size specs of first Dual-Sim Lumia, the Lumia 630 via a leaked product data sheet image. Now, two dual-sim variants of Lumia 630, RM-978 & RM-979 have passed certifications at FCC and both have the same size specs as revealed by their SAR reports. The SAR report also clearly mentions RM-979 and RM-978 as Dual-Sim devices.
Outside of USA, the transmitter of the device is capable of operating also in GSM/GPRS/EGPRS900, GSM/GPRS/EGPRS1800, WCDMA/HSUPA900 and WCDMA/HSUPA2100 bands which are not part of this filing.
 This is a dual-SIM device. As both SIMs use the same antenna and transmitter chain, full evaluation of this device has been made by activating a single SIM only.
Lumia 630 will possibly be released in some markets as Single-Sim 3G device while in other markets as Dual-Sim 3G device. This may explain Lumia 630 image posted by evleaks shows a single-sim device, while the product data sheet image above and screenshot posted before has revealed Lumia 630 as Dual-Sim device.
So, we may be looking at 3 devices,
