HKK Vertex Blue track racing chain (NJS)

The Vertex Blue chain from HKK, Japan.
This chain is black, but appears to shine blue from certain angles.
NJS approved for use in Japanese pro keirin track racing!
This is a 1/8 size chain, standard track bike type.
Beautifully finished, super-tough race chain, with small NJS stamps on the chain links.
This chain uses a quick-link system, like all NJS certified chains.
The Vertex Blue chain from HKK is the highest selling chain amongst Keirin pro track riders.
The HKK blue, gold, and silver chains are all the same, apart from the color finish.