Lacing bones replace the standard grommet/boning structure. Standard corsets are constructed with grommets flanked on either side with flat steels (which provide support and keep the grommets from migrating over time). Lacing bones are very stiff steels with holes drilled into them; grommets are set directly into these bones, rather than just through layers of fabric. Lacings bones are recommended only for clients who are experienced corset wearers and are accustomed to daily wear/tight lacing. The steels are so stiff, they can be off-putting and uncomfortable to someone who is not yet used to wearing corsets. They also restrict movement, which can be detrimental to a wearer that needs to bend and move a lot in their day-to-day.
This item is an upgrade, and should only be purchased as an add-on to your current corset order.