Its a white mascara base with fibres in it. It doesn't hold a curl, does add volume and lengthens lashes as well. But beware of application tactic as it does clump, and this would affect the mascara you apply on this base.
How I use this base:
1) I curl my lashes with a heated curler
2) apply Shiseido mascara base with a light coat
3) I only apply this a tiny bit on the ends of my lashes on top of the Shiseido mascara base so the fibres get on the ends and lengthens the lashes
4) Apply my mascara
End result: Does lengthens lashes when used this way, but probably won't re-purchase.