Review on 🔍 Enhanced SEO: SMALLRIG 15mm Railblock with 1/4"-20 Thread for RED & Other DSLR Rigs - 942 by Elizabeth Keever

Well made and looks like it will last a long time. Supplied with screws and key. I use it with a SmallRig V-Knot to connect the battery to the BMPCC4K rig rails. This works fine if you mount it directly to the V-mount plate, but only if you're happy with the battery all the way back on the 15mm bars (the battery protrudes under the holes the bars go in) . If you want the battery farther along the bars, you'll need some sort of cheeseboard as well.