Ergonomic:Refers to the ability of something that provides comfortable operation for the human body stucture. This DUTY BELT unit is just that. The inner belt expands and contracts with the outter belt. All of the components have to work together, the inner webbing with inner velcro along with outter velcro and outter webbing. All of those components will strech together with every body movement ie: sitting, bending over, or twisting from side to side The expanding material used to obtain these features is man made and as a result testing showed they did not change after over 250,000 times of stretch action,unlike elastic that will breakdown over a short periord, because it is not man made. We have also included a much smaller polymere foot print for the gun holster that can be flipped from one side to another to accommodate the user.