Oil Wool Felt washers, felt seal, 1-Mainly used in absorbing oil. ... 1mm~40mm- density: 0.1g/cm3~0.7g/cm3- used for Medical Devices , electronic, mechanical and so on.USAGE&FEATURE: ... durable, wool won't fall out, good characteristic for oil absorption, heat insulation, seal,dustproof,quakeproof,heat-preservated,sound ... can give you professional suggestions and efficent cooperation! felt washers