Our shim kits are basically 2-3 shims of wood that are laser cut to fit the slot of our collapsible guitars, and are used to adjust the neck angle. Before you consider installing a shim kit, we recommend you first 1) make sure you've fully tightened the main bolt on the guitar. 2) Adjusted the saddle if needed and 3) Adjusted the truss rod if needed. If you've done these things and your string height (action) is still high, you can use a shim kit to quickly lower the action. Here's a link to the FAQ with pictures on how to do the above steps.
Shim kits can be installed permanently with all purpose wood glue, or temporarily. Here's a link to the installation process.
Here are the links to our shim kits if you need one. Please note the shim kits are precision cut for the necks of the corresponding model, so make sure you order the shim kit for your precise guitar.
Shim Kit for Puddle Jumper
Shim Kit for Overhead and First Class Parlor
Shim Kit for First Class Grand Auditorium