|1||Lime (Wheel, as garnish)|
Build in an ice filled Collins glass and stir to combine. Garnish.
Lots of variants here: Tequila can be silver. Soda can be Squirt (traditional in Mexico), Jarritos, or Ting. Some people (PDT, quoting Wondrich) add .5 lime juice. Some people salt the rim, or sub grapefruit juice + club soda for grapefruit soda.