Monteverde Rollerball to fit Montblanc Rollerball Pens - Black One Standard size Montblanc roller ball refill by Monteverde Precision enginnered from USA High quality metal parts with Nickel plated brass tube and Swiss tip Length: 4.42 inch (112.20mm) Nib Size: Medium (0.7mm) Refill Reads: Monteverde USA Rollerball - M22