WILL NOT FIT ANY STANDARD FRAME
Was told by customer will NOT fit 22/45 Mark 2 either

They have made releasing the bolt on the Ruger 22/45 easier.
No more having to manually operate the bolt hold open lever to release the bolt.
Simply pull back on the bolt handle and let it go.

Auto Bolt Release for the Ruger 22/45 features:
Increased contact area for the bolt so it will not wear like the factory part
The plunger and detent hole on the side has been eliminated and replaced by a top hole to create a slingshot effect

Model: VC3SPL-S

The black version is here