I was very disappointed in both the quality and engineering of this product. A work-around for the main issue follows the review. The flaws that bother me in order of significance are:

1) Quality: Very weak soft-metal screws. Using minimal force and a well aligned driver there was some damage to the screw-heads on all 4 that I worked with. 2 of them rounded out so much that I was afraid they would be hard to remove later, causing me to run to the hardware store for higher quality replacement screws.

2) Engineering : The instructions recommend, and the screws (the ones that come with the straplocks) are designed for a #2 Phillips screwdriver. However, a standard #2 driver is too big to fit into the strap-buttons. So you are likely to have to choose between grinding down a screwdriver to fit, or using a #1 which will increase the impact of the first problem above since it is the wrong tool for the job.

3) Engineering : The point of connection for the strap is 5/8th of an inch out from the guitar. The strap button has a radius about 3/16ths of an inch. Therefore any lateral stress (i.e. weight of the guitar) is magnified by more than 3x due to leverage pulling outward on the screw. A 9 pound guitar would be applying a constant 27 to 30 pounds of force on the screw and the wood around it (half that when the weight is distributed evenly on two strap buttons of course). Get a little too active on stage and the level of force could go way higher.

Realistically, if the screws weren't total crap, this might have been a 3 or 4 star review. Once you deal with the fact that a normal screwdriver won't fit and get the things properly installed, it would probably work out for most people. So if you are stuck with a set, here's what I recommend:

Go to a hardware store and buy #6 x 1" oval-head stainless steel replacement screws. Note that these won't fit properly, but they are the closest match and can be modified. (They are 21 cents each at my local stores, and would have cost Dunlop maybe 10 cents more in bulk than what they paid for the crap screws that come with this.)

Put the screw into an electric drill (pointy end in) so the screw head is rotating smoothly when you operate the drill. Run the drill while using a file or a belt sander to take a fraction of the diameter off the screw head. It doesn't need much. I used a belt sander and it took about 20 seconds each. While you are at it, file down a cheap #2 screwdriver so it will fit into the strap button.

Install with the new screws as normal, and recommend that your friends try a different brand!
I was very disappointed in both the quality and engineering of this product. A work-around for the main issue follows the review. The flaws that bother me in order of significance are:

1) Quality: Very weak soft-metal screws. Using minimal force and a well aligned driver there was some damage to the screw-heads on all 4 that I worked with. 2 of them rounded out so much that I was afraid they would be hard to remove later, causing me to run to the hardware store for higher quality replacement screws. 2) Engineering : The instructions recommend, and the screws (the ones that come with the straplocks) are designed for a #2 Phillips screwdriver. However, a standard #2 driver is too big to fit into the strap-buttons. So you are likely to have to choose between grinding down a screwdriver to fit, or using a #1 which will increase the impact of the first problem above since it is the wrong tool for the job. 3) Engineering : The point of connection for the strap is 5/8th of an inch out from the guitar. The strap button has a radius about 3/16ths of an inch. Therefore any lateral stress (i. e. weight of the guitar) is magnified by more than 3x due to leverage pulling outward on the screw. A 9 pound guitar would be applying a constant 27 to 30 pounds of force on the screw and the wood around it (half that when the weight is distributed evenly on two strap buttons of course). Get a little too active on stage and the level of force could go way higher. Realistically, if the screws weren't total crap, this might have been a 3 or 4 star review. Once you deal with the fact that a normal screwdriver won't fit and get the things properly installed, it would probably work out for most people. So if you are stuck with a set, here's what I recommend:

Go to a hardware store and buy #6 x 1" oval-head stainless steel replacement screws. Note that these won't fit properly, but they are the closest match and can be modified. (They are 21 cents each at my local stores, and would have cost Dunlop maybe 10 cents more in bulk than what they paid for the crap screws that come with this. )

Put the screw into an electric drill (pointy end in) so the screw head is rotating smoothly when you operate the drill. Run the drill while using a file or a belt sander to take a fraction of the diameter off the screw head. It doesn't need much. I used a belt sander and it took about 20 seconds each. While you are at it, file down a cheap #2 screwdriver so it will fit into the strap button. Install with the new screws as normal, and recommend that your friends try a different brand!