1/4" - 26 tpi single chamfer Lock Nut, standard Whitworth spanner size of 0.445" across flats.
There are 2 nuts shown for clarity but the price is per nut.
This is a single chamfer 0.150" thick nut made from 303 stainless steel. It is machined back and front for a superior finish and the hexagon sides are hand finished to a semi polish. It then spends 72 hours in a polishing machine to slightly dull the sharp edges and to give them a silky feel so you do not leave cloth particles on them when cleaning the bike
You can buff it to a chrome finish or sand blast it for a cadmium look.
These nuts are in a class of their own and not like the ones turned from hexagon bar you see elsewhere.