What you need to know about
your guitar's Endblock Depth

The Amulet Ultra's endpin can accommodate an endblock depth up to 7/8". This isn't an issue for most modern guitars, but some older instruments may have thicker endblocks. You can check the endblock depth yourself. While looking in the endblock hole, insert a piece of stiff but flexible wire of any sort (like an old guitar string) and look to see when it reaches the inside end of the endblock. Mark the part of the wire that is flush with the outside the endblock hole with a marker or a piece of tape, or bend it at a right angle to the body of the guitar so when you remove the wire from the endblock hole, you can clearly see the depth and measure with it with a ruler.