The table below provides a comparison of wireless barbell tracking sensors; These devices are typically used to measure the barbell displacement, velocity and further derived variables during common resistance training exercises. They are commonly referred to as devices to quantify Velocity-Based Training.
You can scroll left-right (for desktop/tablet) or top/down (for mobile) inside the table to see all products available, and use the search bar to focus
the comparison on one technical aspect. 
There are currently 5 products in this table, from the following companies: Push, Kinetic Performance Technology, Perch, and Blaumann & Meyer Sports Technology UG