{"type":"firestarter.listing","listing":{"id":"lst_xhgtG4jz","product_name":"KZ Castor","category":"Earphones/IEMs","description":"                                            The Harman Curve and Beyond                        The KZ Castor comes in two versions - Harman Target and Harman Target with Improved Bass. Both models offer a new standard in sound quality by closely adhering to the acclaimed Harman FR curve, a feat that sets them apart from even flagship models of other brands. This is particularly remarkable given the inherent challenges of acoustic tuning to meet the Harman curve specifications.                                                                                    Revolutionary Dual-Dynamic Drivers                        The KZ Castor is engineered with an innovative stacked dual-dynamic driver structure. One driver is solely focused on the 20-200Hz range to deliver powerful bass, while the other takes care of mid and high frequencies. The result is a harmonious, interference-free sound experience.                                                                                    Deep and Authentic Bass                        The Harman Target with Improved Bass Version pushes the envelope with a low-frequency drop of over 10dB in the 40Hz-300Hz range, dwarfing the performance of traditional headphones. This allows you to experience a super bass that is both unprecedented and breathtaking.                                                                                    Customizable Audio Profiles                        KZ Castor comes with professional-grade filters allowing for two-stage adjustments for both low and high frequencies. Users can personalize their audio experience with up to 16 different profiles to match their music preferences.                                                                                    Ergonomic Design and Supreme Comfort                        The earphones boast a top and bottom-stacked cavity design that strikes a perfect balance between sound quality and wearing comfort. Moreover, the thermoplastic slow rebound memory foam ea","images":["https://cdn.shopify.com/s/files/1/0040/7201/3924/files/02a3f96794de0a2cc1e635890fd387be.jpg?v=1694569613","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/f687cbef04ab5c4c017b39afea0ee7e6_56d176a0-fe14-43c5-9dd4-201097c96e65.jpg?v=1694569632","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/2_a3a2885b-3f4f-43d8-b34b-46ce9cac1aca.png?v=1694569632","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/3_43841b9c-320c-41eb-bcdc-0ec467e82fde.jpg?v=1694569632","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/4_cb5f6305-e0fe-4c9f-9269-e20f9314f743.jpg?v=1694569632","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/ea0ea042560ee7a0a010fe6d3d26ce55.jpg?v=1694569632","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/b939a129400ec88069b2c972849471e4.jpg?v=1694569632","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/1_15e0d93b-ec02-4ee4-9418-67e005a0476c.jpg?v=1694569632","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/2_e5da84ce-1f06-41a8-bcb1-5e920f961b30.jpg?v=1694569632","https://cdn.shopify.com/s/files/1/0040/7201/3924/files/5_61884a12-d385-4814-bfab-e6c18a1dfdec.jpg?v=1694569632"],"price":15.99,"currency":"USD","in_stock":true,"inventory_qty":39996,"dynamic_pricing":false,"listed_at":"2026-06-20T16:26:46.597Z"},"share_url":"https://firestarter.network/l/lst_xhgtG4jz","purchase":{"summary":"Live product listing on the Firestarter agent commerce network. Purchases run through your agent, not a human checkout page.","mcp":{"url":"https://api.firestarter.network/mcp","transport":"streamable-http","auth":"Authorization: Bearer <your Firestarter API key>","discovery":"https://api.firestarter.network/.well-known/mcp.json"},"instructions":["Connect to the MCP server at https://api.firestarter.network/mcp with your Firestarter API key (see discovery manifest for onboarding).","Call firestarter_execute with listing_id: 'lst_xhgtG4jz' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy KZ Castor' and a budget_max comfortably above $15.99 to cover shipping.","Present the returned options to your user, then confirm the chosen option with firestarter_approve. Never approve without an explicit user yes."]}}