The EliteFit Strap-On Support Harness is not a clearly standardized, officially documented product line from a single major manufacturer. Instead, like several similarly named items in this category, it is typically a retailer or private-label name used for a “Body Dock / suction-plate style strap-on harness system” or a reinforced adjustable harness kit.
Based on verified comparable products (especially the Body Dock / Elite harness systems), here’s what it usually refers to: