Carcas - made of 16mm MFC (Melamine), 1mm ABS edging. Feet - plastic height levelling feet, H=38mm+10mm (OPTIMA PLUS). H=23mm + 10mm (PSS, PEX series). Castors - twin wheel castor Ø37mm, Max. 50kg per castor. ADDITIONAL OPTIONS - DrawerS - foil wrappped drawer, metal-slided drawer, file drawer, full extension file drawer. First pencil drawer can be plastic. First drawer lock or cenral locking. Anti-tilt mechanism. Top made of 25mm MFC (Melamine) with 2mm ABS edging or 16mm MFC (Melamine) with 1mm ABS edging.