Cyndi, if you're asking about the gasket material for the plexiglass front window, you need both parts... the gasket and lock strip. If you're going to try to do the work yourself, be SURE to by a lock strip tool. Using screw drivers and butter knives work, but you'll swear a whole lot less if you spend the <$15 and get the tool made for the job.
Ten Forward - 2014 Escape 5.0 TA
Double Yolk - 1988 16' Scamp Deluxe