Fom the Lathes Ltd link to product.
“Kerry “Super 8” & “Drillmaster” drive belt. UK or EU-made high-quality, machine-tool grade belt with an invisible joint that, unlike the cheap imports, does not bump as it goes around the pulleys and so ensures the smoothest possible drive.”
I’ve been caught before with buying cheap belts from bearing suppliers, sometimes it doesn’t matter – for your mower for example – But they do tend to have a lump where the joint is, not something I would want on a pillar drill.
“You pays your money and you takes your pick” as they say.