if they're like the ones I had for a while 700c. I think so called 27" tubs = 700c. Careful though-i think they develop splits easily around the spoke holes when building up-mine had these...
I have laced my constrictor rims up and it turns out there is a tiny split in the front rim by one of the spokes.
To my eye those rims on eBay do not look like a set.
https://www.ebay.co.uk/itm/Constrictor-tubular-alloy-rims-32-40-hole-27-x-1-1-4-/164806975180?_trksid=p2349624.m46890.l49286
Do these actually take 700c tubulars?
Were 27” tubs a thing?