Abstract: One aspect of the invention involves a honeycomb panel insert for use with a honeycomb panel. The insert comprises a generally cylindrical body having a cylindrical outer peripheral surface, a first end, an opposite second end and a longitudinally extending passage having a first opening in the first end and a second opening in the second end. The first opening has a first perimeter and the second opening has a second perimeter that is relatively smaller than the first perimeter. The longitudinally extending passage has a first section having a first diameter, a second section having a second diameter that is relative smaller than the first diameter and a third section having a third diameter that is relatively smaller than the second diameter. The difference between the first and second diameters provides a first ledge and the difference between the second and third diameters provides a second ledge.

Abstract: A drain plug has a stud that has a head and a shaft joined to the head. A resilient swell sleeve is frictionally mounted on the shaft and is sized to fit within a drainage hole. First and second cams are mounted on the shaft. The first cam abuts the swell sleeve and does not rotate with the shaft. The second cam rotates with the shaft. Rotating the stud in a first direction causes the first and second cams to engage each other so as to produce an axial force that causes the swell sleeve to swell so as to create a seal between the swell sleeve and the drainage hole. Rotating the stud in a second direction terminates the axial force thereby allowing the swell sleeve to return to its normal shape so that the drain plug can be loosened from the drainage hole.