Sure Claw has been designed for guitarists who use a tremolo system with sustain block. It helps maintain the correct spring tension. The tension can be adjusted without removing the back cover plate.  With the Sure Claw you eliminate the following:

• Using an extra long drill, drilling diagonally into the guitar body
• Using a very long, special cross-recess screwdriver (and a lot of muscle) to unevenly screw in the two fixing screws
• Running the risk of slipping with the screwdriver and damaging the guitar
• Repeated, tedious removal and re-attachment of the spring compartment cover, just for the sake of readjusting the tension springs.