Nomad Design Lipless Crank Baits explained - by Damon Olsen. 

Even though they look very similar, there is a significant difference between the Swimtrex and the Swimtrex MAX lipless crankbaits, as explained in the following video by Nomad lure designer Damon Olsen. 

SWIMTREX - Patented Autotune™ technology works together with a pat. Pending body design that allows the Swimtrex to swim when sinking and also vibrate when lifted. The Swimtrex has the LEAST vibration of any of the Power Trio and is a more subtle vibration. It is perfect for Yoyo techniques on a fall and rip and is also amazing when pulled fast through grass. It tracks straight, vibrates when lifted for the perfect Yo-yo style lipless. Work it either in shallow water swimming into the grass and then ripping up, or in deeper water for schooled up fish yoyo style. Available in 3 sizes - 66 (1/2oz), 72 (3/4oz) & 80 (1oz).

SWIMTREX MAX - Patented technology creates an incredible vibrating action like nothing you have ever fished. Part of the Power Trio Lipless Crankbait System! This thing THUMPS hard! It emits vibration at dead slow speeds right up to fast burning retrieve and can be used in a variety of situations whether you are fishing deep or covering ground searching the shallows. Available in 3 sizes - 57 (1/2oz), 66 (3/4oz) & 72 (1oz).