It holds a curl. Does it so well that I can use any non waterproof mascara over the top and it'll be ok.
For better results preheat your eyelash curler with a blow drier and then curl your lashes.
Only downside is that you have to use makeup remover to remove the mascara if you use this base.
This helps mascara's stick to my lashes. For some reason most mascara can't grip onto my lashes and it looks uneven without this.