600/700x21 Race Valved Inner Tube
Tube size 600/700x21 with nickel plated metal valve stem. A good thickness and most importantly correctly dimensioned butyl inner tube produced by Blockley on tooling specially made for the job (as all other tubes in our large Blockley range). You cannot buy a better product than this.
The metal stem has some advantages over a rubber stem as outlined in our article on valve stems on this site.