What are "jumelles" in French?

Search: jumelles, jumelle

Why: On reddit, Ulric Collette Splits Portraits to Show Facial Similarities in Family Members:

PORTRAITS GÉNÉTIQUES

Mère / Fille: Francine, 56 ans & Catherine, 23 ans

Soeur / Frère: Karine, XX ans & Dany, 25 ans

Père / Fils: Denis, 53 ans & William, 28 ans

Jumelles: Laurence & Christine, 20 ans

And so forth. (There are more.)

Answer: "Binoculars"!

What?

Oh wait, also "twins"!

Apparently only a specific set of twins.

Source: Google Translate

The More You Know: And a video:

Portrait génétique from Ulric Collette.