MontBlanc Belts. SKU: 131166. Barcode: 4062037111247. Size: 120 x 3.5 cm. Montblanc M Lock 4810 Grainy Leather 35 mm Belt. This 35mm grey leather belt features a transparent M LOCK 4810 buckle showcasing Montblanc's emblem, combining the sporty appeal of soft grain leather with a climbing-inspired design and an easy-to-open mechanism for adjustable strap length.