Even if you call PHD seems to ignore requests for more detailed specs. No idea why they want to be so cagey given their market for this product. An educated guess given their temp rating would be ~4oz max though. Depends on how dense the baffles feel and look.
My EB Downlight 50 with 10D shell had 4oz of FP950 and weighed 10oz. in an XL but also had a full zip with zippered handpockets that doubled as a stuff sack. And a similar spec'd RAB Continuum is ~11oz with 4oz of FP850.
But this PHD jacket uses a heavier coated ~20D shell and 10D inner which probably negates the weight savings of a half zip and pass thru hand pocket. Anyway, the pics of it in use don't give the impression the baffles are chocked full like my EB Downlight 50 or the RAB Continuum.