The Wing Sung Junlai 630 Wrench is a compact metal maintenance tool designed for disassembling and servicing the piston mechanism of the Junlai/Wing Sung 630 fountain pen. The Junlai 630 uses a piston filling system, and compatible wrenches are supplied with or sold for servicing this mechanism.
Please Note: This is a maintenance/disassembly tool and should be used carefully. Incorrect or excessive force during disassembly may damage the pen or internal components.