Size: Backpack size Chest legs spacing suit for weight
S: 28 * 18cm 18 ~30cm 10cm 2.5kg
M: 32 * 20cm 24 ~43 cm 13cm 2.5~ 3.5 kg
L: 38 * 23 cm 36 ~50 cm 15 cm 3.5 ~ 6.5 kg
XL: 42 * 24cm 43 ~ 60cm 18cm 5.5 ~ 9.5kg