Fill a shaker with ice.
Pour gin, Cointreau (or Triple Sec) and lemon juice into the shaker.
Shake vigorously until the outside of the shaker is very cold.
Fill a lowball glass with ice.
Strain the shaker into the glass.
Fill the rest of the glass with Cal & Gary’s Sparkling Meyer Lemon Water.
Squeeze the lemon wedge over the glass and drop in.