If you have a bong that doesn’t match your bowl you can use a bong adapter.
Bong adapters provide the option to use a wrong-diameter bong/bowl combination. However, you still need to make sure that the adapter you get fits both items. You can do this by measuring the pipes that connect both parts. The bong part of the adapter should be male in most cases, whereas the bowl often needs a female part to connect to the adapter or bong.
If you are unsure about which item to get you can send us more information about your bong and bowl so we can advise you on the right adapter to buy.