- 45 ml (1 1/2 oz.) vodka
- 90 ml (3 oz.) grapefruit juice (red or pink)
- 45 ml (1 1/2 oz.) club soda
- Ice cubes
- 1 grapefruit slice cut in two parts
Combine all the ingredients in a highball glass filled with ice cubes.
Stir using a mixing spoon.