Please note this is the current (as of 2018) Sidi replacement buckle, I did not have to swap the strap on my 2014 shoes, but I have some 2003s for which the standard is different. Swapped out for a useless sproinged buckle in two minutes. Way cheaper than new shoes.
I was able to install the buckles on my shoes in just a couple of minutes. All of the necessary parts for installation were included, except for the required tools which I already had. The buckles work well and I am satisfied with the outcome.
I bought these to replace the buckles on my Genius 5's (the springs on the old buckles just stopped working-both left and right simultaneously). I tried inserting the strap into the new buckle, but the strap was too big (I didn't read the part about the old strap not fitting with the new buckle). The problem was these two little plastic tabs that were preventing the strap from entering the buckle. So I cut these little tabs off and now the strap fits fine. It's not a perfect fit because once the strap is secure in the buckle, the red part is raised a bit, which tells me the newer strap is probably thinner and less wide...? This does not bother me, though, because they are functioning properly.
Two big crashes this year and two wasted buckles. Thankfully the buckles are not only easy to replace but also reasonably priced. My straps were getting a bit beat up so I replaced them as well and everything felt like new.
The new ratchets work very well. Easy motion and a definite click, whether tightening or backing off. I didn't realize that the old ones were getting progressively worse to use. I only replaced them when one broke.