This Bits Kit for Quick Connect/Disconnect Attachments provides 20 spare rubber o-rings for connectors located on the back of the Data Acquisition System Interface. O-rings eliminate air leakage from the computerized polygraph by maintaining a tight connection. When o-rings wear out, they should be replaced using the silver cone-shaped device shown in the photo. Simply place the large end of the silver cone onto the connector and place the replacement o-ring on the small end of the silver cone and roll into place. Supplied in a small plastic box.