3" Expandable Caster- 3GDEC300
Caster inserts into tube end held in by an expanding rubber grommet from the interior of the tube. 300 lb weight capacity per caster.
Turn the top jam nut and snug on the rubber spacer. Place the caster into a tube. If loose in the tube, tighten the jam nut until the rubber touches the tube sides. When inserted, twist the large lock ring until the rubber locks in the tube. See fig. 1