No.6 1000-pc Kingyo Sukui Goldfish/Superball fishing paper net refills

Approximately 98mm in diameter.

No. 7, for professionals (even weaker) is the weakest type, which is a special-order item, and we always have it in stock.
No. 6, normal (weak), for up to 10 goldfish.
No. 5, a little stronger, for up to 20 goldfish.
No. 4, strong, up to 30 goldfish.
The manufacturer’s description for No. 4 (up to 30 goldfish) says [superballs allowed], but this is just a guide.