According to the newest rumours, which may or may not turn out to be true, Sirocco will have pretty neat specifications. IP67 water and dust-proofness? Check. Zeiss certified 12mpx + 13mpx dual rear camera & 5mpx front camera? Check. 3250mAh battery? Check. Snapdragon 835 CPU? Check, although some people believe that it will actually have an even newer Snapdragon. 128GB storage? Check. Lastly, 5.5′ OLED display? Yep, check.
Again, these are just rumours, and ones that do not come from any 100% quality sources. All we know is that HMD plans on Sirocco being a real high-end device, therefore the high-end specs listed above are all possible.
By the way, we have also heard that HMD wants to unveil Nokia 1, Nokia E71 (2018) and Nokia 7 Plus soon. Exact date is unknown, but it will probably take place in MWC 2018, between February 26 and March 1.