What does this cost to the nearest dollar?

Title: 18V to 20V Battery Adapter for Dewalt 20V MAX  
Category: Power Tools Accessories  
Brand: Qbmel  
Description: Converts Dewalt 20V MAX lithium batteries to run in most Dewalt 18V tools.  
Details: Supports DCB203‑DCB206 and DC9096/98/99 series NiCd/NiMH batteries; no charging required and meets FCC/CE/ROHS standards.

Price is $