Well yes, the groove allows the wire to pass from the gearbox through the buffer tube, and then into the stock. Picture it without that groove there (ie solid material) how would the wires go from the gearbox into the buffer tube?
If you take it apart you'll see what I mean.
You can get a regular one and dremel a groove through it. Or you can get the ones I posted.
CA doesn't sell direct to the public, retailers only, they handle orders in excess of $100,000 daily to dealers worldwide so random dudes asking for $20 spacers are pretty low on their priority list.
If you want one you know where to find me.
