a turret nut is a nut that has two slots. It's self locking.
The turret nut is available at Anemo and comes in metric Class 8 yellow zinc plated ROHS conform and stainless steel A2 and A4
You can also get the turret nut in UNC and UNF in class 8 steel clear zinc plated as standard product.
Other versions of the turret nut or double slotted AUTO-Lok nut can off course be obtained.
You can find the standard turret nuts here: