Khaki "GI Trousers Belt" used by USMC for field use. The buckle is an open type buckle shared by NAVY / MC, which is different from the one of ARMY / AF. Made by VANGUARD, which has been known as a trousers belt supplier since the WWII, it is exactly the same type as the one delivered to the US Military.

Manufacturer: VANGUARD
Belt:
• Color: Khaki (Tan)
• Material: Cotton 100%
• Width: 1 1/4 inch (32mm)
• Thickness: 3mm
• Length: 55inch (139cm)
Buckle:
• Type: Open Buckle shared by NAVY / MC
• Material: Brass
• Marking: "US FB" or "VANGUARD"
• Measurements: 4.8cm x 4.3cm (W x H)
End Chip:
• Material: Brass
• Finish: Plated in Gold Color
• Width: 1 1/4 inch

Note) The length regulation of the trousers belt in the US military seems to be that the belt end is about 1 inch (about 2.5 cm) from the 1st belt loop when worn. Please cut it to the length you like and use it. You can easily open it by inserting a flat-blade screwdriver into the gap between the buckle and belt end.