The kit I ended up purchasing from KAK Industry was their KAK Super Sig SB-15 Package Deal w/ QD endplate. This kit comes with the FDE SIG SB-15 Brace, KAK Super Sig Tube, Chrome Silicon Carbine Spring, H2 Buffer, KAK QD Endplate, Castle Nut and 2 Length Adjustment pieces. This kit comes with a lot of parts, the part that I liked the most was the 2 Length Adjustment pieces, this helps you adjust the length of pull on your pistol and keeps the SB-15 Brace nice and tight. I was able to adjust my Sig SB-15 Brace to the same length as the stock I have on my AR-15 rifle.
The one thing that makes the KAK Pistol Tubes so good is that they are specifically designed for the Sig SB-15 Brace. This makes for an exceptional fitting with the brace. With the KAK Pistol Tube the Sig Brace fits securely on the buffer tube. Putting the Sig SB-15 Brace onto the KAK Pistol Tube takes a little bit of work since the brace fits so tightly on there, but once you get in on there and adjusted the fit and feel of it is phenomenal. I highly recommend this kit to anyone who is going to be building an AR-15 Pistol with the Sig SB-15 Brace.
- Factory SIG Arm Brace -FDE
- KAK Super Sig Tube
- Chrome Silicon Carbine Spring
- KAK QD Carbine Endplate
- Castle Nut
- Length Adjustment Kit