Pace 1213-0087-P10 - SX 100 Front Seal, Pack of 10
The front seal should be replaced regularly as it will become stiff and brittle over time with use. Once it begins to stiffen and cracks, the vacuum seal around the end of the desoldering tip will begin to leak. For best results, make sure the seal is always soft and pliable and when it becomes stiff replace it.