400x19 Inner Tube
A thick correctly dimensioned Blockley butyl inner tube, with rubber valve stem.
This rubber valve stem type is used where the hole in the wheel rim is the larger 11.5mm size. More often than not the rims that take a 400x19 tyre size have the smaller 8mm valve stem hole. The Blockley range of inner tubes are the best that can be produced, not only because they are thicker and made from the best material from our own tooling, but taking the 400x19 tube as an example, this tube is only for a 400x19 tyre. Not for a 350x19 (which has it's own tube) or a 450x19 (which has its own tube) and so on.