Lee Sporting LS5 Complete Trigger Group Full-Size Semi-Shelf for SP5 (not compatible with K or pushpin clones)
Rounded hammer so you can run without the short stroke buffer. Buffer is included just in case you need it for some reason.
Installed machined "pre-fit" trigger and detent with milspec safety. Replace with your preferred selector to rock and roll. I've used this extensively with my SP5 and it's been 100% reliable.