Abdominal Ab Trainer Six Pack Twister Core Crunch Machine Sit-Up Exercise with Resistance Straps & LCD Monitor Twister, Crunch, Sit Up Abdominal Exercise Machine with Resistance Bands Rolling back Cushions Massaging the Back while Working out at the same time. Adjustable Strength with 4 Strings, 2 Strings for intermediate workout and 4 Strings for Maximum Workout. Padded Swivel Seat that Twists and Turns, LCD Monitor counts Calories, Time, Count... Abdominal Chair designed to workout lower Abs, Upper Abs and Obliques.