Ruger Mk III HSS Ease-Of-Assembly Upgrade
The new HSS (Hammer Strut Support) is a parts upgrade that greatly improves the ease of assembly for Ruger MK I, II, and III pistols (not 22/45 nor Mk IV). It simply eliminates the problem of the hammer strut becoming jammed in the cross pins of the pistol grip when you are trying to re-assemble your pistol.
In the photos above, you can see the HSS part as well as the problem and how HSS solves it. With the HSS installed, the hammer strut cannot get jammed. This is because the HSS fills in the open space where the strut used to get jammed in.
Easy Installation Video