The First Team FT5001 Chrome Ground Socket For 3.5 Inch Volleyball Uprights are designed for use with 3 1/2 Inch diameter volleyball uprights. The 10 Inch deep socket is perfect for use on floating wooden floors, synthetic/tile floors or concrete floors. It also works great as a mower safe socket for outdoor grass of cement courts. This is for one floor socket. Requires two sockets per system.