A hand controlled compactor for the compaction of ground work, paving etc comprises a base plate, carrying both a rotatable, out of balance mass and a motor or engine, with a drive connected to the mass to impart vibrations to the base plate, an operator’s handle also being provided, the motor or engine being attached to the base plate via a plurality of anti-vibration, shock-absorbing mountings. Each compressed code has a word length sufficiently long to identify all instruction codes included in the program. The filter can include a hub and a plurality of legs or wires or segments extending from the hub, wherein at least a portion of the hub or a portion of one or more of the legs or wires or segments is modified to provide an enhanced echogenic characteristic of the filter or a portion of the filter. In the system, the sliding restraint is sized, in coordination with a fixed sleeve accepting a core wire to actuate the restraint to effect an anchoring function with the sleeve so that the stent is not inadvertently advanced during deployment.