tesa 4163 tesaflex EL is a robust soft-PVC electrical insulating tape 19 mm wide by 33 m long, in blue for phase identification. The plasticised film with a UV- and weather-stable acrylic adhesive resists ageing on both indoor and outdoor circuits. The tape stretches to conform around joints, terminations, and irregular shapes while retaining stable dielectric performance. Supplied in packs of six rolls, it is a workshop staple for electricians and other trades.