A unit purchase is deemed to exist if the parties agree on a concrete, already individualized object of performance, which they know exactly or which is present at the time of conclusion of the contract. The delimitation to the generic purchase is primarily in the will of the parties and subsidiarily in the market view. The distinction is important for the bearing of risk as well as for the differentiation between liability for material defects and non-performance.
German: Stückkauf (765)
Source: LK-Lötscher, 11.05.2020