How to install the GK pickup

Normal Method
This method is for an electric bass (4-string) that has sufficient space for the controller on the front.

Measure the distance between strings.
Measure the distance between the strings of the bass. You can easily measure this by placing the gauge that is printed on the GK-3B package, under the strings. In this example, the distance between strings is 19 mm.
Adjust the divided pickup.
Adjust the divided pickup in accordance with the distance between strings. First, loosen the screw on the side of the pickup.
Move the marker so it matches the string intervals, then re-tighten the screw. The marker position is 16mm at the innermost side and 19mm at the outermost. For this bass, the string interval is 19mm so you should align it to the outermost side.
There are two markers. Adjust both markers identically.
Determine the pickup installation position.
Position the two markers directly under the G and E strings (on this bass, these are first and fourth strings) and position the pickup so it is within 50mm of the bridge bearings. Use tape to mark these positions.
Adjust the height of the pickup.
Put the spacer under the pickup and adjust the height. There are three types of spacer: a 3mm, a 1mm, and a 0.25mm type. With the protective paper of the spacers still on, try various combinations and adjust so that the interval between the strings and pickup is 1.5mm when the strings on the highest fret are pressed down.
Note: Since the thickness of the spacer's two-sided tape is 0.1mm, keep that in mind when determining the number of spacers
Verify the fourth string using the same method.
When the height of the first string and fourth string differs, adjust by cutting and affixing the included pickup cushion or spacer. Adjust in the same way when the bass body is curved rather than flat.
Secure the pickup to the body.
Remove the strings and affix the spacers.
Affix the pickup onto the spacers, applying sufficient pressure to secure it.
Verify the installation.
Check once more to verify that there is no problem with the position and height.
Adjust the pickup cable length.
Temporarily position the controller where you will be installing it on the body and see how much excess pickup cable there is.
Place the excess pickup cable into the back of the controller.
Install the controller.
Remove the three screws from the back of the controller and use them to secure the controller to Holder A.
Press Holder A onto the edge of the bass body. On the rear side place Holder B so the assembly is secured with the bass body in between.
Secure Holder A and Holder B by tightening the 5 x 20mm cap bolt.