This is a Faber Castell TG drafting pen set from around the 1980s. The separate case contains only the yellow attachments. The set includes four pens: 0.25mm, 0.35mm, 0.5mm, and 0.7mm. There is one pen body, an ink bottle, and attachments in a plastic case. Judging from the product and design, it's likely from the 1980s. Rotring is the most well-known brand for drafting pens, but Castell is also a good choice. The ink is old, so it's best not to use it. Faber castell TG 80s