A problem with Holosun is Chinese quality control consistency. We have samples of one doing fine, but many others not so much. I started with 2 HS507Cs. After both were exposed to water, one failed. Holosun replaced it. The replacement failed from normal use. The third one may still be fine but is currently in its box as a potential 4th line backup (after RMR T2s, 2.5 MOA SROs and 5 MOA SROs).