42While contracting authorities enjoy a broad discretion in that regard, which is justified by the fact that they are better placed to know which supplies they need and the requirements which are necessary to achieve the desired results, Directive 2014/24 nonetheless sets certain limits with which they must comply. Contracting authorities must, in accordance with Article 42(2) of Directive 2014/24, read in conjunction with Article 18(1) thereof, ensure that the technical specifications afford equal access of economic operators to the procurement procedure and do not have the effect of creating unjustified obstacles to the opening up of public procurement to competition (see, to that effect, judgment of 25 October 2018, Roche Lietuva, C‑413/17, EU:C:2018:865, paragraphs 29 to 33).