Pinnacle V Jammer was developed to increase the effectiveness of training, whlist also helps you maintain body position in the water. Jammer's new distinctive power stitches highlight key muscle groups around your legs and encourage you to be more involved in these muscle groups. Pinnacle V Jammers also benefiting from the support of major muscle compression panels around the waist. By focusing on these key areas, you can help improve your technique and speed by achieving correct body positioning in the pool. Jammers are made with Speedo's Endurace + Material, which consists of PBT and polyester fibers; This prevents chlorine from being harmful, frayed and faded.