Joule Shield Steel Post Pinlock Insulator Strainrite’s premium range of Joule Shield™ Insulators. Featuring the multi-shield design. This allows for a greater surface area and shielding for minimised power leakage. PROVEN 100% GREATER INSULATION THAN OTHER TESTED INSULATORS Computer aided designed twin pinlock provides a strong accurate fit for locking. Reinforced web bracing and thicker walls providing structural strength. Rounded surfaces that shed water faster. Joule Shield™ Twin shield flange for increased insulation performance. Long-life UV stabilised plastic. Proudly designed and manufactured in NZ. 12 Year Guarantee.