Material: 

Upper: Smooth nappa leather
Lining: Chrome-free leather
Insole: Microfiber insole + leather
Outsole: Thermo rubber

What we love about these barefoot shoes: 

Wide toe box
Flat, thin and flexible outsole
Low shoe weight
Comfortable against the skin, snug fit and very well-made

Fit and size advice: 

Width: Suitable for narrow to wide feet
Volume: Suitable for low to high instep - this model also works well for a high instep thanks to the lacing that goes far down on the foot.
Size: Large in size, you may need to choose a size smaller than usual. Follow the size chart.

Froddo Barefoot Leather Laces are made from eco-friendly, natural leather. GRS certified. They are soft in material, durable and long-lasting. The shoes are manufactured in Croatia under strict European regulations.
Weight: 290 g (size 39)
Care instructions:

Clean as needed with Collonil Bamboo Lotion and a damp cloth. Use a shoe cream, such as Collonil Organic Cream, to keep the leather soft and protect against moisture and dirt.

Size chart
Measure the foot by placing it inside a box or with the heel against a wall. Put weight on the foot and measure to the longest toe. This is your foot measurement. Add 0.5 - 1.5 cm to this measurement to find the right size. Compare with the shoe's inner measurements below.
We have verified these measurements at Widetoes: 
Size: length / width

36: 23.8 cm / 8.8 cm
37: 24.6 cm / 9 cm
38: 25.2 cm / 9.2 cm
39: 25.7 cm / 9.4 cm
40: 26.6 cm / 9.5 cm
41: 27.2 cm / 9.6 cm
42: 27.9 cm / 9.8 cm