Requests for these regularly pop up here, so I thought that I'd post this link.

A buyer would still need to source the mounting hardware, but it's a start and the seller doesn't mind a haggle.

YAMAHA XT250 XT500 DT100 DT175 DT250 DT400 PAIR OF FRONT INDICATORS XT DT | eBay

 

We have them on ebay available to UK customers too.
341-83312-70 Indicator Lens Completed

For international buyers, they can be bought on our website:
sumorubber.com/341-83312-70-indicator-lens

Please be aware, most of the replacement lenses on the marketplaces are not E-marked, so if your MOT regulations require certified lens covers, ours will not be good enough. But we will be getting some E-marked OEM lenses coming soon.