Attaching sphere
= Attaching sphere
{title2=$S^{h-1}\times\{0\}$}
The attaching sphere of an index-$h$ handle $D^h\times D^{n-h}$ is $S^{h-1}\times\{0\}$ in the previous boundary. Its <framing of an embedded sphere> identifies a neighbourhood with $S^{h-1}\times D^{n-h}$ and specifies the <handle attachment>.