The PROIRON Resistance Band Set are made of hundreds of eco-friendly natural latex threads that provides strong resistance and perfect elasticity, these are protected by a premium polyester coating and a further movable Plastic layer adds a further layer of protection. Due to the covered thread deign they are sure not to snap. Two soft cushioned, anti-slip and sweat-wicking foam handles protect your hands from injuries. The metal hook and carabineer rings are sturdy and will not distort or snap even under strong tension. The door anchor is thickened and soft so it will not damage your doors. This fitness band set is perfect for the gym, yoga, Pilates, as home fitness equipment for strength training, outdoor or indoor workouts to shape your perfect body. Each home gym resistance bands have different resistance levels, Black(30lbs), Red(25lbs), Orange(20lbs), Green(15lbs), Yellow(10lbs). Exercise bands can be used alone, or stack used together to meet your different exercise stages needs