L.J. Smith Stair Systems M65744 Single Orb Acrylic Baluster Low Sheen Black 1/2" x 1/2" x 44" in the Stair Balusters & Accessories department at Lowes.com
Plexiglass Acrylic PMMA Staircase Pillar/Balustrade/Railings - China Acrylic Pillar and Acrylic Balustrade