Lego 1 Black 10x10 wedge plate with cut corner no studs in the middle NEW | eBay
LEGO part 89523 TAN Octagonal Base Plate 10x10 Center Hole | eBay
LEGO Blue Building Plate - 32 x 32 Studs (10" x 10") - $4.99
BrickLink - Part 6063 : LEGO Plate, Modified 10 x 10 Octagonal with 6 x 6 Open Center [Plate, Modified] - BrickLink Reference Catalog
Base Plate Building Platforms for Building Bricks Compatible with Lego Classic, 10 "x 10" Single-Side and 10 "x 5" Double-Sides Base Plates can be Used to Build Double-Layer Buildings (Multicolored)
LEGO Green Building Plate 10x10 (626) New and Sealed 4294464 42884006266 | eBay
LEGO Blue Building Plate (10" x 10")
LEGO Blue Building Plate (10" x 10")
LEGO 626 Green Building Plate (10" x 10") (Discontinued by manufacturer)
LEGO Plate 10 x 10 10x10 Octagonal w/ Hole 89523 (1 pieces) Choose Color C | eBay
LEGO Black Modified Plate 10x10 Octagonal Open Center w/4 Yellow Tile 6455 #6063 | eBay