Designed for breeding, isolating or acclimatizing fish or shrimp, the Marina Hang On Breeding Box is a safe & secure nursery for livebearer fish that
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I've got one, here in Queens 11374, though with gas and tolls, you can probably get it shipped from Amazon. If you happen to come down here, will trade it for a couple of frags or what ever. Just looked at it, I have all the parts. It has a 1/2 gallon capacity.
Though the device is advertised to be used with an air pump, a power head is much better. Personally I directed a water exhaust line from another canister into it, which then flowed into the aquarium.