SL Stands for "Spend Less"! Clamp on bird bath is made from a steel ring that's 14" in diameter. Simple but sturdy! Includes the green plastic (BPA free US made) dish with the perfect 1-1/4 " depth. Heavy duty clamp features a large easy to tighten turning knob. The ring has a powder coated black finish. Clamps to hand rails up to 2" thick.