Finding Blanket Fill

Hi!

My Arabian/Quarter Horse gelding has this Tough 1 blanket that the previous owner gave to me when I got him. He is in his teens and being from the warmer part of the state, he shivers a bit if he is wet or it gets really cold. I have another horse now who can use my gelding’s blanket, so I would like to get my gelding a new one. I don’t know what the fill is on his blanket, and the tags have been cut off. Is there any way to find to fill of a blanket?

Thanks!