uni-ball one UMR Ink Refill / uni Mitsubishi Pencil UMR-38S you can use TRC Pencil

you can use TRC Pencil Refill (38070006)

Material (Inner case): Polyester

The SMAND Pen Case doubles as a smartphone stand—featuring a magnetic flip-down flap with non-slip rubber treads—so you can access your pens with your phone propped vertical or horizontal at just the right viewing angle

Laser-engraved scale for lasting readability

Multiple color options available—ranging from neutral to vibrant hues—offering both function and personal style

uni-ball one UMR Ink Refill / uni Mitsubishi Pencil UMR-38S you can use TRC PencilThis is a new gel ink ballpoint pen characterized by a new development of gel ink and a simple, straight barrel design. Compared to typical gel ink pens, the black ink appears even darker and stands out distinctly when reviewed later, allowing you to create impressive notes. Note: This refill is compatible with all uni ball one pens.