Yes, these are THE knife hair clips Kathyrn Newton wore in the Lisa Frankenstein movie!  These are a smaller version of the iconic hair pin made in Austin, TX by Vinca! 
If you're interested in BIGGER knives, may we suggest our 4" Chef's Knife Barrette worn by Aubrey Plaza at the Child's Play (2019) premiere?

This one has an alligator clasp to grip all kinds of hair. Sold separately. See alternate images for pointing right vs pointing left.

• lightweight plastic acrylic knife
• spring loaded steel alligator style clip
• don't worry, it's not sharp and won't cut your hair!
• measures approx 2.5" long x .5" wide