The HB shock is arguably the smoothest 1/12 shock built, unfortunately it isn't made anymore. There is alternative though
http://www.reflexracing.net/Team-Pri...et_p_2232.html it uses a set screw to hold the spring perch on just like the HB shock did. The Team Prime shock is an upgraded version of the HB shock with a tinitride coated shaft and machined piston.