Their center heights and mounting pitches of housings are same as SN5, so they use larger housings with smaller insert to mach the dimensions. The smaller O.D. size has reduced load carrying capabilities and may lead to shorter bearing life. The long time SN5 users can’t expect the same bearing lives to those unitized SN5 units. We use the standard adapter sleeves in our patented CROSSLOC™ and this is why we are 100% compatible with SN5.
We are trying to be competitive on price as much as possible even with one size bigger inserts than others to achieve our goal. That is to replace all SN5 in the world with our SN to make them easier.