The teeth are resiliently deformable to allow a hollow duct to be fitted over the neck portion and have either sharp edges or barbs thereon which dig into the internal surface of the duct to retain {HEAD ~ the duct} on {TAIL ~ the neck portion} of the joiner 
The teeth are resiliently deformable to allow a hollow duct to be fitted over the neck portion and have either sharp edges or barbs thereon which dig into the internal surface of the duct to retain { HEAD ~ the duct } on { TAIL ~ the neck portion } of the joiner
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH