{"type":"firestarter.listing","listing":{"id":"lst_-H4Pmhnv","product_name":"Engineered Plastics \"Full Sized\" Rollerball Cartridge/Felt Tip Pen - Ultem/Black Ultem","category":null,"description":"Natural Ultem and Black Ultem\nThis page is only for the rollerball/felt tip version of the pen. Full details can be found here for the fountain version!\nThese pens come with both rollerball cartridge (Schmidt 5888) and felt tip (Schmidt 6040) cartridges included. The 5888 is a silky smooth writer with a ceramic tip and proprietary tech to keep it from drying out even when uncapped for extended periods, while the 6040 is a spring-backed felt tip cartridge with a super unique feel that offers a fine lined, marker like writing experience.\nThe material is Ultem aka PEI (Polyetherimide) and is able to be machined thinner than most acrylic pens and yet will be stronger than acrylic to resist accidental drops or mishaps.  \nThe o-rings will keep the pen sealed so excessive tightening of the section to body and cap to body is not necessary. \nCapped length -127.5mm (5.02”)Uncapped length - 122.5mm (4.80”)Grip diameter min - 10.2mm (.40”)Grip diameter max - 11.2mm (.44”)Body diameter - 13.5mm (.530”)Weight - 1/2 oz or ~ 14grams (Ultem and Black Ultem)\nThe cap does \"post\" and it is very comfortable to do so due to the extremely light weight cap. \nWhat chemicals can I use to clean this pen? Soap and water or Alcohol is fine on this material for deep cleaning (one of the benefits of Ultem and Peek!)\nWhat chemicals should I not use? Windex. Ammonia based chemistry, It has been brought to my attention that some pen flush has ammonia, use that only on the nib/feed. It is easy to unscrew the nib unit and do that, if you need help ill make you a video to show you how.\n ","images":["https://cdn.shopify.com/s/files/1/0281/7862/products/BlackUltemMarkerBP.jpg?v=1641499200","https://cdn.shopify.com/s/files/1/0281/7862/products/NatrualUltemMarkerBp.jpg?v=1641499200"],"price":250,"currency":"USD","in_stock":true,"inventory_qty":9999,"dynamic_pricing":false,"listed_at":"2026-06-18T20:47:17.254Z"},"share_url":"https://firestarter.network/l/lst_-H4Pmhnv","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_-H4Pmhnv' — this pins the purchase to this exact listing, skipping product search — plus request: 'Buy Engineered Plastics \"Full Sized\" Rollerball Cartridge/Felt Tip Pen - Ultem/Black Ultem' and a budget_max comfortably above $250.00 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."]}}