We've found these bang-for-buck butyl inner tubes from one of our suppliers. Features an elusive black coloured Presta valve stem.

Lightweight race tube - claimed weight of 85g for the 60mm valve variant.

Specifications
Branded "VEE"
700c 23-28mm
Removable valve core
Dual locknut system
Made in Thailand

Mfr Claimed Weight
85g (60mm)