Pace 1213-0090-P5 - Replacement O-ring
The Pace 1213-0090-P5 is a Pack of 5 O-Rings for the TD-100. This O-Ring is used to secure the tip and forms a protective seal to ensure the electrical connections in the TD-100 are always clean. They will wear out with normal use from the tip being inserted and pulled out and need to be replaced periodically.