What kind of filling is the Primaloft Gold mentioned in the pants description?

In the product description for GOYOWEAR's PRIMALOFT WEATHER PANTS, you first see this filling as the name of the insulator. The material filled inside the pants is PRIMALOFT® GOLD processed from 100% polyester^[1][2].

The biggest feature of this material is that it is resistant to moisture. When commonly used natural down absorbs moisture, the feathers easily clump and collapse, flattening the air pockets and turning cold. On the other hand, Primaloft filling is intertwined with a microfiber structure that does not absorb water, so it maintains warmth even when wet from snow or rain and dries quickly^[3][4].

In addition, the 40d water-repellent nylon used as the outer fabric first repels moisture hitting from the outside^[5]. This means you can move comfortably without worrying about the pants sagging damply and robbing your body heat, even in harsh weather with blowing sleet or snow piled on the ground.

hmmm, a synthetic filling that preserves its lofty air pockets even when wet clearly demonstrates its utility when walking outside in bad weather.