J-Bead, J-Hook, Unibead, and V-Bead are the same thing. . This type of swimming pool liner looks like it has an upside down "J" on top of the pool liner. The upside down "J" fits onto the top of the pool wall. This type of swimming pool liner has only been on the market for less than 10 years. Unfortunately it is expensive and does not last as long as an Overlap pool liner or a Standard Beaded pool liner. They tend to shrink and pull inward, causing a shorter life span. Therefore, it is not a good idea to purchase this type of replacement pool liner. The good news is that you can adapt a J-Bead to an Overlap. Overlaps last the longest and are the most affordable. You can replace with an Overlap, however, remember to buy coping along with an Overlap replacement liner. It is very easy, less expensive, & will last much longer on average.