The System 4000 air excavator manufactured by Vacmasters and distributed by Sewer Equipment can provide the brute force to dig deep down with air, exposing utilities in hard soils without harming them. It is effective in soil that is hard, wet, sunbaked or compact, including ground frost. This unit provides operators with seven to eight minutes average potholing time and efficiency in backfilling with no mud hauling or disposal costs. It includes remote operation, a low-maintenance design, hydraulic-powered dumping, supervisory control panel, self-purging filtration system and fast-acting interceptor canister. 800/466-7825; www.vacmasters.com