Vibro-Curb has integral, vibration-dampening spring isolators that are said to be easy to access. The curb provides mounting for rooftop units and includes a 2 x 4 wood nailer for attaching roofing felts. Roofing may be completed at a later date without disturbing the unit. A flexible 9-in. counter-flashing provides a weather seal while permitting access to the isolators. Roofing around spring access ports is not required. The isolators are said to provide a minimum 90% efficiency. Custom sized and spaced to accommodate the unit’s weight and center of gravity for optimum dampening, the isolators can have deflections of 1, 2, or 3 in. Vertical-limit stops eliminate excessive movement caused by wind loads and seismic activity. Units can be fabricated to match a specific roof pitch or configuration.