At times you will get shoes that have the cleat mount positioned lower than normal and you need a slightly longer bolt to reach it. These bolts will save the day in those cases. There is also a 10 mm length of you have a shim between the cleat and the sole, or if the mount is even lower.
LBS did a excellent bike fit for me Including adding shims under my shimano Cleats for better power transfer but after a few Rides I noticed screws kept getting loose
That's I noticed they were to short with added shims
Searching I found bike tires direct sold a longer Replacement set of screws. Worked perfect
No more loose screws