MARKHAM Landscape Products carries a large selection of Keystone retaining wall materials. We carry the Garden Wall blocks in three colors: Pewter, Sandstone, and Red/Black. Our supply of Standard, International Compac, and Cap Units includes: Gray, #40 (Williamsburg) Brown, and #36 Brown. We carry a full line of components such as straight-face and sculptured-face blocks, straight-face and sculptured-face caps, angle-side and straight-side caps, corner units, fiberglass dowels, kapseal adhesive, and geogrid soil reinforcing material. INTERNATIONAL COMPAC Size: 8"H x 18"W x 12-1/4"D Exposed Face Area: 1 sq.ft. 8" x 18" Weight: 85 lbs (38.45 kg) Click here to visit Ketstone Walls showroom STANDARD UNIT Size: 8"H x 18"W x 21-1/2"D Exposed Face Area: 1 sq.ft. 8" x 18" Weight: 95 lbs (42.75 kg) CAP UNIT Size: 4"H x 18"W x 10-1/2"D ExposedFace Area: 1/2 sq.ft. 4" x 18" Weight: 45 lbs (20.25 kg)