12x12 Plastic catch basin (BASE 300-CBP), downspout guard, A ClassVodaland's 12x12 BASE plastic catch basin is a square basin with a 12" width, length, and height. This catch basin comes with an 8" height plastic downspout guard. This grate is specially designed to collect rushing water from your downspout. The basin can be connected to our 4 Base plastic trench drain when used with a riser, and has pipe connection outlets in diameters of 2, 3, 4, and 6 on all four sides. Each basin features an internal debris