4.00x19 inner tube, correctly dimensioned with an offset position rubber valve stem. Made from the best material butyl, but also with a nice thick wall sectionas tubes were in period - made on new tooling produced by Blockley. These tubes hold air like no other!

Our rubber valve stemmed tube is used where the hole in the wheel rim has the 11.5mm size.  More often than not the rims that take a 400x19 tyre size have the smaller 8mm valve stem hole (for which we also produce an inner tube with a metal TR6 valve stem). 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 this 400x19 tube as an example, this tube is only for a 400x19 tyre. Not for a 350x19 (which has it's own dedicated Blockley tube) or a 450x19 (which has its own dedicated Blockley tube) and so on.