Had some email to explain if these will work in different models.
Yes a single registered sear will function in all roller lock 90 series gun. 23, 91, 93, 94, SP-89
Own one of these registered sear and you can put them into any
semi auto pack. It is illegal to use a full auto pack, besides these won't fit into FA packs.
Notice the difference in packs.
A single pack will function for all HK 9 series family of firearms and their clones such as Century PTR and Vectors.
A full auto bolt is also required , but most of these gun from parts kits already have them installed from the manufacture.
Below are stock photo , not mine.



