I'm assuming it's window glazing? plastic

Hello! They haven't made aluminum glazing bead in a long time, but I think one of our vinyl options will work just fine. Start by examining our 55-204. This has a very similar shape to your original and I think is a great place to start, as long as the dimensions all line up.

Profile view of 55-204

Sure, if the 6' length is no good then this can be cut to size without issue. I like to use a utility knife, but you could also use shears. Whatever you prefer. It's just vinyl so it will cut easily.