Check the listing for details. Dayton Audio OA-4 Outrigger Speaker Spike Set with Steel Base 4 Pcs. Condition: New. Listed at 35.44 USD. Improve the stability of your speakers while giving them a professional look with Dayton Audio's OA-4 steel outrigger spike set. Constructed of 4 mm thick steel, these 165 mm (6-1/2") long spiked outriggers have a durable black powder coated finish. With 3 mounting points per outrigger and a heavy duty spike, this 4 piece outrigger set is suitable for speakers weighing up to 400 lbs. (100 lbs. per outrigger).Improve the stability of your speakers while giving them a professional look with Dayton Audio's OA-4 steel outrigger spike set. Constructed of 4 mm thick steel, these 165 mm (6-1/2") long spiked outriggers have a durable black powder coated finish. With 3 mounting points per outrigger and a heavy duty spike, this 4 piece outrigger set is suitable for speakers weighing up to 400 lbs. (100 lbs. per outrigger).