From this page:

Crupi's I-Beam stems are CNC machined from 6061-T6 billet aluminum and are amongst the lightest stems on the market! The I-Beam features extensive external machining; the stem is visually appealing yet stiff and strong. The CNC-machined and embossed Crupi logo on the faceplate gives this stem its unique look.

The Crupi 0mm "No Reach" stem has 0 mm of reach, which means the stem holds the bars directly above the steer tube, making the bike's front-end length shorter.