Shoes were being put into the vulcanizer at Fung Keong Rubber Manufacturing Factory at Shau Kei Wan Road. Vulcanization was a process that cured raw rubber by heating it with sulphur to improve its elasticity and strength. The purpose was to hold the upper and sole of the shoe more firmly together.位於筲箕灣道409號的馮強樹膠製造廠內，鞋隻正送入硫化機。硫化處理是利用高溫使加了硫的天然橡膠變得更具彈性和強度，鞋底和鞋面也銜接得更牢固。