Aluminum Dual Rated Parallel Groove Clamp for 1/0 STR - 6 SOL Aluminum Dual Rated Parallel Groove Clamps are high strength aluminum extruded alloy fittings assembled with steel or anodized high strength aluminum flat washers for heavy duty service entrance or for use as a heavy duty distribution armor rod clamps. The serrated grooves provide increased contact. Supplied pre-filled with oxide inhibitor. Rated 600V. Temperature rating 90 degrees C.,