Where can I get a 4.5mm SRAM DUB spacer?

My Google skills have failed me. Where do I find a 4.5mm SRAM DUB spacer?

Like this:

Or the gold bit in this:

If anyone has one spare, more than happy to buy it, or if someone can point me in the direction of a shop that sells them I would be very appreciative.

You have to buy the whole kit – Google SRAM SPARE – BOTTOM BRACKET SPACER KIT DUB MTB/ROAD (DUB SPACERS 2.0, 3.0, 4.5, 6.0, 6.5, 9.0MM AND 2 STANDARD BB SPACERS) and you should find one. If not PM me and I can sort you one.