$0.20 – $0.50
The rear 5.5mm hex drive is an intuitive way to build that leaves external tool flats unmarred. At a minimum it’s a second interface that can facilitate repairs in tricky situations. The Polyax design is a semi-spherical profile where the nipple meets the rim. It acts like a ball joint for improved spoke-nipple alignment, which can be further enhanced by pairing with Polyax washers. This nipple is configured with a screwdriver slot to accept a conventional nipple driver. Overall a total package of all the features you want and none you don’t.
Normally ships in 24 hours.