Damn, I guess they just sent you half the miner. The S7's weight is 4 kg. Your package is 2.3.
The APW3-12-1600-B2 is 2.3 KG's tho.. I wonder..
It says on the tracking page that the department number is "power supply" so I suspect he'll receive his PSU tomorrow, not the miner.
Also FWIW, UPS tracking said that my review copy miner weighed 3.0 kg, so a little less than that 4kg estimate.