inner tube sizes:
Nr. 5 := tire diameter 355 to 400mm (17", 18"), tire width 32 to 40mm
Nr. 6 := tire diameter 406mm (20"), tire width 28 to 40mm
Nr. 7 := tire diameter 406mm (20"), tire width 40 to 62mm
valves:
SV := Sclaverand, Presta, French, slim valve with 6mm valve stem
AV := Moto valve, about 8mm valve stem
DV := the classical german bicycle valve, about 8mm valve stem