To get right seal you'll need to remove a portion of the seal to get the side profile of your current seal. There are multiple types of applications for slide-out seals; Glue On, Peel-N-Stick, Press In, Push On, and Slide-On. There are multiple styles and measurements the seals; some come with a bulb, some don't.
For example the Rubber Wiper Seal and Bulb for RV Slide Out - Stick On - 60' Long x 3-3/16" Wide # SR68FR you were looking at will come with the bulb and is a press on design... view full answer...