Complex sentence: Member states cannot prohibit the "making available" (sales and distribution in EU speak) of such CE marked products and cannot prohibit the use of such products as long as the declared characteristics satisfy all national requirements.
Split into simpler sentences: Member states cannot prohibit the "making available" (sales and distribution in EU speak) of such CE marked products. Further, member states cannot prohibit the use of such products as long as the declared characteristics satisfy all national requirements.