hi there. Like former profesional handball player ill love to help to explain how this bands working cos company made little be of confusion. I bought two complets all together 12 of bands. I fell very bad cos i didnt have them when i was young. Many injuries will be prevented. I dont agry whit company they dont working like gravity. I ataching them on bars and combinating them whit weights. Cos of that i have two complets. So they making gravity force stronger or whit band u can do ur sesion whit gravity forse more massive planet than earth. After while when im not using bands feels like no gravity. Or u simple feeling like somebady trowing on u weights from 3 floor{when im using them} Apart from streinght u building explosive power. Problem whit body builders is ego.Ego is to high but this band are not for ego maniacs there are for real people who whants to be a beast like ragby players for example.Also can be used for dead lifts same like for pullups. All u need is two hooks on the floor,ataching band , u standing in the middle and puting band bihande neck and lifting weight from floor or lifting urself on bar for example. It is umbelivible progres whit dose bands. I attaching them on every peace of equpment in gym same like every tree in the park plus short and explosive runing sprints when puting 4 bands together around my weist. All the best for company no mistake whit elastitone.