From the product description, check product page for current description, price and availability:

The redesigned (patent pending) Nukatap Flow Control Faucet features an exclusive Nukashuttle valve that improves laminar flow for reduced foam and turbulence. As in all Nukataps, first pour foam reduction is achieved through a a reduction in thermal mass by the use of molded rather than stainless interior parts. The tap is often the warmest part of the draft system as it protrudes from the beer tower or refrigerator. As a result, it acts like a heat sink and only works well once enough cold beer flows through it to cool the tap body down. By making the inner shuttle out of lightweight food grade plastic, thermal mass is reduced.

Flow control is best for customers who are often switching from one beer style to the next and want maximum flexibility in their draft system (we generally recommend flow control faucets for customers who dispense commercial kegs, not home brew). The redesigned Nukatap Flow Control is also the first forward sealing tap ever manufactured that can be used with an auto close spring return.

The new NUKATAPS have been manufactured with a 2.5 degree reverse angle. This allows for a wider range of taps handles to be used, in particular, long and/or heavy handles to work perfectly irrespective of the installation conditions.

The Nukatap FC is the worlds first forward sealing tap that has a auto close spring (our part number I23). This means when you fit the optional spring you can let go of the tap handle and the tap will automatically close. Great for kids, pets, or clumsy buddies.