The gear couplings made by Lovejoy are dynamically balanced, high performance gear couplings that comes in up to 30 sizes and can be custom made for a specific application given the detailed information needed to design the coupling to be perfectly suitable for the application. Body fixated bolts are fixated at the reamed holes and its fasteners weigh balanced. It comes in four varieties: FHS High Speed Close Coupled, FHSA High Speed Standard, FHSAA High Speed Precision, FHSPAA High Speed Ultra Precision, and FHSMA High Speed Marine. The FHS has much tighter tolerances and is similar to standard F Type gear coupling. The FHSA are dynamically balanced and piloted gear fit.