This is a kozuka (small knife handle) featuring a design of an ascending carp. The listing provides no specific maker or period information. It is currently available for purchase.

We could not find an authenticity certificate on the seller’s listing. Japanese swords and fittings are normally papered by the NBTHK (or the NTHK). Without one, the attribution is the seller’s own assessment and has not been independently verified — treat it with caution and ask the dealer about certification before buying.
This is a kozuka (small knife handle) featuring a design of an ascending carp. The listing provides no specific maker or period information. It is currently available for purchase.

We could not find an authenticity certificate on the seller’s listing. Japanese swords and fittings are normally papered by the NBTHK (or the NTHK). Without one, the attribution is the seller’s own assessment and has not been independently verified — treat it with caution and ask the dealer about certification before buying.