{"type":"firestarter.listing","listing":{"id":"lst_4jRmnKPy","product_name":"#5 Nib Unit","category":"#5 Nib Unit","description":"Sales here include the nib, feed and housing. All of our individually sold nibs get our 7 step testing and tuning process, the same as when included on pens. \nNote that most reported nib issues come from individual nib sales, so it's crucial that you use the proper technique to install and remove nibs. See our video here of our recommended method: https://www.franklin-christoph.com/pages/recommended-method-for-changing-removing-replacing-a-nib#5 nib units fit Franklin-Christoph Models 14, 25, 27, 28, 29, p40, 45, 45L, 451, 55, 65 Stabilis, and more to come.High Performance Steel is more like gold today than most nibs you'll find through pen history. Solid Gold is softer and the nibs will write a little wetter. We use 14k nibs for our gold choice as we feel this alloy gives the best performance. Our solid gold nibs also get a rhodium plating for a silver color, but the logo is cut in relief, showing the yellow gold in the diamond shape.All sizes are \"Western\" and equivalent to most US or European brands.\nStub Italic Gradient (S.I.G.) nibs are tips ground in house at Franklin-Christoph.\n\n\n\nLines sizes based on our Blue 72 ink, on our sugar paper, using medium pressure. *Note that the Cursive Calligraphy (cc) nibs are factory designated actual tip sizes.\n\n\n\nFactory Line Approx. Sizes:\n\n\n\nXF = Extra-Fine .4mmF = Fine .5mmM = Medium .6mmB = Broad .8mm1.1 = Cursive Calligraphy *1.4 Cursive Calligraphy *\nNagahara Line Approx. Sizes:\n\n\n\nN = Needlepoint .25mmFI = Fine Italic .55mmMI = Medium Italic .7mmMS = Medium Stub .7mmBI = Broad Italic .9mmBS = Broad Stub .9mm\n\n\n\nS.I.G. Line Approx. Sizes:\n\n\n\nSIG F = .55mmSIG M = .7mmSIG B = .9mm\nFor more information about nib differences, visit our Nib Detail and Info page.\n\n\n\n","images":["https://cdn.shopify.com/s/files/1/0023/7679/4187/products/10NibHPSteel.jpg?v=1568401239","https://cdn.shopify.com/s/files/1/0023/7679/4187/products/10Nib_Solid_Gold.jpg?v=1568401296","https://cdn.shopify.com/s/files/1/0023/7679/4187/products/10-1.1_1.4_HPS.jpg?v=1568401302","https://cdn.shopify.com/s/files/1/0023/7679/4187/products/HW_5_BW.jpg?v=1569257572","https://cdn.shopify.com/s/files/1/0023/7679/4187/products/HW_5.jpg?v=1569257586","https://cdn.shopify.com/s/files/1/0023/7679/4187/products/HW5nibsmedleyonblack.jpg?v=1618506874","https://cdn.shopify.com/s/files/1/0023/7679/4187/products/HW5nibsmedleyonwhite.jpg?v=1618506876"],"price":20,"currency":"USD","in_stock":true,"inventory_qty":179982,"dynamic_pricing":false,"listed_at":"2026-06-18T20:47:20.899Z"},"share_url":"https://firestarter.network/l/lst_4jRmnKPy","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_4jRmnKPy' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy #5 Nib Unit' and a budget_max comfortably above $20.00 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."]}}