Features and benefits: slide nut with female thread, washer and BIS RapidRail spring. This product is ready-to-use / pre-assembled for quick fixing ... retains assembly in place before final tightening. It replaces a tee-nut, washer and threaded rod with 1 piece assembly. No need to measure and cut rod! Conforms to MFMA Metal Framing Standards (Metal Framing Manufacturers Association; Plenum rated - tested to ASTM E-84.