There are three models included: 1.5mm, 2mm and 3mm. These values represent the distance from the tip of the bottom blade which, at its closest is about 1mm from the tip of the top blade. So, the 1.5mm or 2mm guards are probably closest to the standard #1 guard.

The big differences with these guards are that the tips are rounded and that the comb teeth are much wider. This helps prevent cuts to bumps in the skin and reduces scratching of the skin's surface. 

The intended use is to hold the clippers with the cutting tip pointed directly at the skin, rather than with the bottom blade parallel to the skin. Because the comb teeth are wider, you'll need to do multiple passes, but you're much less likely to damage the skin in the process.