These are the late WWI M1918 cartridge belts made from canvas instead of webbing. Designed to hold 100 rounds of M1903 Springfield ammunition on 5 round stripper clips, they work equally well with the M1 Garand en bloc clips. Unlike their later M1923 counterparts, these lack the retaining strap for the stripper clips. This actually makes it slightly easily to get to your M1 rifle ammunition quicker.
They saw extensive use throughout WWI and well into WWII, both in the ETO and PTO. If you look hard, these can be seen in many period photos right up until the end of hostilities.
Condition of these is very good to excellent. Some may have storage dirt and marks, but they're not rotten. Shades, dates and manufacturers vary, but as always, we try and send the nicest examples first. For over 100 years old, these are excellent.