Every R151 vacuum is extremely portable, fully grounded and non-sparking by impact. The vacuum housings are indestructible and include a LIFETIME WARRANTY. The Ruwac exclusive Microclean primary filter is 99% efficient at .5 microns and includes a 3 YEAR GUARANTEE. Ruwac engineered the R151 to be the LOWEST MAINTENANCE COST vacuum on the market. This means less frequent filter changes, reduced clogging of filters, resulting in less downtime, more savings and more production.