Glazing Bead?

Empire Pacific Ali Class A. House was built around 1990. Was checking the windows over and this vinyl piece was completely crumbly. I think it's called a glazing bead? You can see under the external part that broke off it's kind of a fin or something. The one on the bottom looks different to me (not sure if it actually is) because it's a more narrow slot. The external part on the outside of the window is about 3/4" wide. Any help would be greatly appreciated! I gently pried and it basically turns to powder it's so old and UV exposed.