Luffa sponge: vascular bundle of fruit. In summer and autumn, the fruit ripens, the peel turns yellow, the inside is dried, picked, peeled and peeled, washed, dried and seeded. Saponins, bitter substances, mucus, wood glue, citrulline, xylan and interferon in luffa have certain special functions. Contains vitamin b 1 for preventing skin aging and vitamin C for whitening skin, which can protect skin, eliminate plaque and make skin white and tender. It is a rare beauty product, so Luffa juice is called "beauty water". Luffa sponge is composed of criss-crossing vascular bundles, mostly rectangular, slightly thinner at both ends, with a diameter of 5 ~ 10cm, varying in length, yellow-white and rough surface, sometimes with residual skin and pulp, light weight, tenacity and elasticity, three cavities in the cross section, and occasional black seeds. A slight breath, a faint taste. It is best to be large, complete, clean, tough, yellow and white and seedless.