Complete Exercise Set: you will receive 20 sets of resistance bands, 5 different weight levels resistance loops of each set, equipped with small black carry bags, and 20 pieces of reflective backpacks; The complete combination can meet your daily exercise needs, and you can share them with your family members Various Size to Meet Divers Needs: each set of the workout bands measure about 600 x 50 mm/ 23.62 x 1.97 inches, and different thicknesses correspond to different weight levels; The thickness of 0.4 mm corresponds to 5-10 lb, 0.5 mm corresponds to 10-15 lb, 0.7 mm corresponds to 15-20 lb, 0.9 mm corresponds to 20-30 lb, and 1.1 mm corresponds to 30-40lb, to satisfy your different exercise requirements