In {HEAD ~ this way}, {TAIL ~ the toe centralising elements} can provide two functions, namely centralising and levelling, while providing a compact mechanism for achieving these two functions 
In { HEAD ~ this way } , { TAIL ~ the toe centralising elements } can provide two functions , namely centralising and levelling , while providing a compact mechanism for achieving these two functions
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH