Designed and manufactured in Canada, the new Pro-Blu 933 wire connector was developed with the installer's needs in mind. With an ergonomic design and a wide range of approved wire combinations, this wire connector is a perfect fit for the majority of residential and commercial applications. Made of durable polypropylene resistant to temperatures up to 257 deg F Posi-Grip™ surface, finger-friendly plastic Ergonomic twisting wings Rounded secure edge Approved for 600 V maximum copper building wire and 1000 V maximum in signs or lighting fixtures