压缩空气管用非金属装置 Fittings (Compressed air pipe –), not of metal 旋瓶盖用橡皮圈 Jar lids (Bands of rubber for unscrewing –) 橡皮减震器 Buffers of rubber (Shock-absorbing –) ..
Additionally, the rims on each jar are thought to have supported lids that would be placed on top until the body decomposed, adding credit to this theory.