Copa de balón
The large stemmed balloon a Spanish gin and tonic is built in. The size is the technique: it takes a full load of ice and a long pour together, which is what lets the drink stay both strong and cold, and the wide bowl holds the botanicals over the surface where a narrow glass would let them go.
Capacity
Solid ice only, filled as a highball is; a copa is packed, not garnished with a few cubes. The figures are scaled from the same ratios as the highball and Collins on this site rather than measured for this shape: cubed near 57% of capacity, a single block about 95% of that, crushed about a quarter more than cubed. Crushed is taken as 7% above cubed: loose crushed ice weighs about 593 to 640 kg per cubic metre against 917 for solid ice, roughly 65% solid, where loose cubes run about 61%.
Every drink below was checked against this figure at build time. A recipe that does not fit its stated vessel fails the build rather than shipping.