The BLK-31 corner block enables the creation of 2,3,4,5 and 6-way corners with FD/HD31 single tube. Attachments such as BLK-SCON-ST (Steel 1/2 connector) or BOB (Bold-On Receiver) are bolted to the corner block. In this way, all configurations of 90 degree angles are possible. This makes it a perfect, easy-to-use, creative and cost efficient product.