As a licensed manufacturer of Allan Block SRWs plus several Keystone and West Block retaining wall products, ORCO offers a complete line. Like pavingstones, popular Allan Block SRW’s are sized to create unique patterns . . . use 1, 2, 3, or 4 different sized block in a wall design. Blends and solid colors with a wide variety of segmental wall finishes, allow designers and homeowners greater flexibility. Also, engineered for commercial applications.