The Hendrickson Concentric Collar is a practical and reliable product designed to enhance your automotive experience. With its zinc-plated construction, this collar offers durability and longevity. The 1/2" SQ adjustment drive size allows for easy installation and adjustment. Measuring at 1 3/4" in length, this collar fits perfectly with small outside diameters of 1 1/4" and large outside diameters of 3 3/4". The 1/2" flange thickness ensures a secure fit. Sold individually, this collar is compatible with OE parts such as Automann MHS91 and Hendrickson 64097-000 / 64633-000 (Primaax).