Safco Products 2655BL RSVP  Pneumatic Base with 4 Levelers  (Top sold separately), Black Pneumatic Base RSVP pneumatic table base Pneumatic table base adjusts in height from 27 3/4" to 37 3/4" Four leveler glides on base Use with Safco Products 30" Round RSVP Table Top Models 2651CY, 2651GR or 36" Table Top Models 2653CY, 2653GR, sold separately Safco Products optional locking Casters Model 2660BL, sold separately