What can you bring into a baseball game.

Also no weapons....including pocket knives.

https://www.mlb.com/mariners/ballpark/information/guide BOTTLES, CANS & OUTSIDE BEVERAGES No bottles, cans or outside beverages may be brought into the facility, with the exception of: One (1) clear, factory-sealed plastic water bottle (32 oz. or less). Guests may bring in empty plastic bottles and fill them at any of the water fountains located throughout the ballpark. Medications. Baby bottles and unopened, soft-sided, single-serve containers (such as small milk cartons and juice boxes; no twist-tops allowed).