Click photo to enlarge.

This extra tube set is used for the following kits:
- Sierra Button Click Pen (FOR REGULAR SIERRA BUTTON CLICK ONLY) They may be trimmed very slightly (1.5mm) to fit the Elegant Sierra and the Elegant Beauty Sierra style button click pen kits.
- Sierra Letter Opener

Dimensions

Notes:
- Though very similar, these are not interchangeable with the regular twist Sierra tubes.