Description from Blichmann Engineering:

The HopRocket is an incredibly innovative hop infusing tool packed with world-class features! It can be used as a hopback, but it also doubles as an inline hop infuser (Randalizer) for your beer-dispensing system.

• Operates up to 40 PSI
• Holds up to 3 oz of whole hops as a hopback and 4 oz as an infuser
• All stainless steel construction and silicone seals
• No need to monitor the wort level because it will never overflow
• Fully enclosed system from kettle to fermentor means no hop aromas are lost!
• Optional HopRocket Mounting Kit to easily integrate into your TopTier modular stand
• Inlet at the bottom allows air to purge and reduce hot-side aeration
• Fine filter with wiper seal sends clear wort to your fermentor
• Coarse filter with cone bottom inlet prevents wort channeling
• Fill with up to 3 oz of rice hulls to use as an inline filter
• Works on gravity systems and with pumps! (About 4 feet of static head is recommended for best gravity performance)
• Doubles as a hop infuser (randal) for your draft dispensing system. 
• 1/2" Male NPT inlet & outlet make it easy to adapt to quick connect or camlock fittings