Like legal quotas, voluntary quotas can be a way of ensuring a “fast-track” access of women to parliaments. However, the proportion of women to be nominated usually varies between the political parties, both in intra-national and cross-national comparison. Among the parties with a 50% quota for women on party lists, there are, for instance, the Green parties in Austria, Germany, Iceland, Italy and Sweden, as well as some leftist parties in Germany, the Netherlands and Sweden. In several cases also “zipper systems” are applied. Other parties have opted for gender quotas, usually between 20% and 40%.