Here are three examples of the Zaino's used by the Italians in WW2.
No. 1 is the Alpini back pack. This is a large open bag pack, with a internal divider. It has 8 straps on the outside, to carry a blanket roll or Telo Tenda. The main flap is closed with two grey green lether straps, and the lid of the flap has web straps to hold the Gavetta in place. A cavernous bag fo the Alpini troops to carry everything they need.
No.2 is the M39 Large pack. This was issued to all troop types, and is often confused as being an Alpini only issue. The Alpini did use them, alongside the Alpini version, but it did not replace the Alpini design. Contemporary photo's show this pack being used in North Africa by troops and Para's. It has outer straps to hold blanket/great coat and telo. It also has two large outer pockets to hold 'need to be at hand' items. The interal bag part is just a large sack, with no dividers.
No.3 is the smaller M39 march pack. This has 5 outer straps for carrying blanket and telo. Its large flap is closed with either two leather straps and sam brown fittings or with canvas strap and buckle arrangements. Internally it is divided into three compartments. This Zaino was designed to be placed into the main M39 back pack as a pre made assault rig, and therefore just removed when required for a 24hr assault was planned.
All these packs are made from olive grey green canvas. One common feature is the white cotton name tag sewn on the inside of the flap, for the use of marking the soldati's ownership.