Scala Black Fountain pen by Lamy - Nibs Plus Ultra
Escala is a scale-ruler pen by Ensso with imperial and metric scales
BeeMall Multifunction Pens With 6 Functions in 1 - Pen, Measuring Scale, Stylus, Gradient set, 2 Screw Drivers With a Magnifying Long Card(Colour May Vary)[Imported from Germany] : Amazon.in: Office Products
Shigeru Ban Designs Retractable "Scale" Pen Inspired by Architect's Ruler | ArchDaily