Features: can only be seen under the irradiation of lamp
You can use glass pen, pen, pen
Great to draw or keep a diary
You can also use it to record some important things, such as passwords or other things, which others find and think are blank
Widely used for writing, drawing, art craft.

Specifications: size: 18ml Size
Length:6.6cm(2.6in)
Width:3cm(1.18in)
Height:3cm(1.18in)

Package Includes: 1Piece Invisible Inks

note: 1.Please allow 0-1cm error due to manual measurement. make sure you donot mind before bid.
2.Due to difference between different monitors, the picture may not reflect the actual color