[ciupicri]

Pinhead & Hexlox barely say how they work or offer any instructions and they're also quite expensive compared to cheap bikes.

[SamBam]

They're simply skewers that can't be removed by a standard wrench, but instead require a weird wrench with a semi-unique combination.

Could you still hack one? Sure, given time and forethought, but every other bike near you will have quick-release or regular hex nuts.