The weak side hand placement works with out a special thumb rest. Thumb rest from Ronni works on MCK In order for you. Shoulder strap attaches on either. No pistol brace extension required. MCK makes use of pistol's slide launch so no mal-features like Ronni. The one thing the Ronni https://garrettkmyns.blogdanica.com/25966675/getting-my-recover-20-20-to-work