The Loadstar is 3 things; a Grip Strengthener, a Fidget Spinner, and a Fist Load/Knuck.  It weighs 112 grams as pictured, or just about 4 oz.  The scales and core are grade 2 titanium with brass and copper hardware.  Be sure to watch the video to get a sense of the action.
 
2 internal springs provide moderate resistance and increase the fidgetability of this immensely satisfying  piece of kit.