What cocktail has vodka grapefruit juice and elderflower liqueur?

Here's the classic recipe:

* 2 oz Vodka

* 4 oz Grapefruit Juice

* 1/2 oz Elderflower Liqueur (like St. Germain)

Instructions:

1. Fill a highball glass with ice.

2. Add the vodka, grapefruit juice, and elderflower liqueur.

3. Stir gently to combine.

4. Garnish with a grapefruit wedge.

Let me know if you'd like variations or other cocktails using those ingredients!