DESCRIPTION ystudio’s special design spring cap structure. You can feel it’s uniqueness no matter from appearance or from the way using it. It’s a solid brass crafted pen and is very durable. You can use it no matter while you’re working or traveling. SPECS Material：Brass Specs：9.5 X 11 X 138 mm Refills：Parker type ballpoint pen refill (Incompatible with gel ink refill) USE&CARE The color of brass would be changed by different users and various environments yet this is also its unique feature. The oxide is harmless. It would restore its original luster by wiping with copper oil. Without any surface treatment, we hope each product can mantain its individual marks by the constant use of owner. Please experience and enjoy this one-of-the-kind beauty of brass.