BLUEROCK RB1 Rolling Base Upgrade for 4" Z1WS, 8" Z1, 10" Z1 Specifications: This is an optional upgraded stand base/footing for models: 4" Z1 W/S, 8" Z1 & 10" Z1 This base is more robust, wider and longer than the standard base and has convenient tilt and roll wheels Base Measures: 13.5"x10" (standard base measures 8.5"x7") Total Dimension with wheels: 14.5"x14.5" Includes Base, 2 Wheels, 2 Pillar mounting bolts and 4 Corner Leveling Bolts Unbolt your standard Z1 base from your the pillar and install this larger base (The standard Z1 base pictured is shown for scale and not included in this listing) FREE GROUND SHIPPING TO THE LOWER 48 STATES. CONTACT FOR OTHER PLACES UNLESS OTHERWISE POSTED.