Cement and Frac Pump Parts factory Best-all supplies plunger packing set assembly for HT-400, SPM600S, SJ300, SJ600 TPH400, TPD600 plunger pumps, including fabric-rubber V -packing, head ring, back-up ring, lantern ring, seal and packing carrier. 100% interchangeable with OEM parts Available from 3-3/8" to 5".Cement and Frac Pump Parts factory website:http://www.bp-mudpump.com/cement-and-frac-pump-parts/