I installed this in a 1991 Honda CRX Si. The original OEM boots have different sizes for the driver side (left side) and passenger side (right side). The old boot measurement on the driver side (left side) is 46-47 mm diameter for the large hole side measured from the inner opening. The equivalent measuring points on the PSA42529 large hole side is 40 mm diameter. So, there is a 6-7 mm difference between the OEM and the 3rd party boot. This made it very difficult to install on to the steering rack. I was able to finally attach it by using a small screwdriver to stretch the boot opening around the rack end. As for the passenger side (right side), the old boot measured 35 mm diameter measured from the inner opening of the large hole end. The 3rd party 1aauto PSA42529 part also measured 40 mm diameter. So, the old boot had a smaller opening and thus made the 3rd party boot install much easier. I gave it 5 stars for the passenger side, 3 stars for the driver side, which averages