Most cans are 3.8 ounces, and at least one travel/mini option is listed at 1 ounce.
Shake the can well before use, hold it about 6 inches from the underarm, and spray onto the underarm.
Several listings include a flammability warning and list the product as flammable.
Most dry sprays list 72 hours of odor and wetness protection; one 'Maximum Protection' dry spray is described as providing 96 hours.
The listings show aluminum-based actives: Aluminum Sesquichlorohydrate (examples include 15.2% and 12.2%) and formulations that list Aluminum Zirconium as the primary active.