Extruded and CNC-machined from 6061-T6 aluminum alloy, Box One Cassette Spacer Kits feature a super lightweight minimalist design and provide anywhere from 1 to 10 millimeters of spacing adjustment. They are compatible with Box One (aka Harmonic), and Box Three Pro and Mini hubs and are sold in packs of four.

Each pack includes the following spacers:

• (2) one millimeter
• (1) three millimeter
• (1) five millimeter