You'd have to check the contract specs.
A lot of times you'll have multiple symbols for what looks like the same month/strike combo but the contract specs are different because it reflects a special case condition (maybe they changed the delivery quantity to 150 shares because of a split or there's a merger/spinoff involved and the option reflects the special conditions of that - e.g., some cash delivery, delivery of variable shares or shares of more than just the underlying stock, etc.).
All option contracts are not a simple 100 shares delivery - you should always verify the specs of the contract before you trade it - i.e., always know what you're trading before you trade it.
