Flexifoil have created what could possibly be the best handle so far for quad line foils.  The new Flexifoil ProLink handles ship standard on the Blurr and are available seperately as well to put on your Blades / Rages / Bullets or any other brand of kite that operates on 4 line handles.  Flexifoil's attention to detail on these has been superb.  The idea behind the bolt through the top of the handle could possibly be an evolution of Sylenz's own "handle bullets" that he designed to suit the original Flexifoil handles, mounting a bolt / pin from the top.

Grip & Feel
The grip of the handles is very gel like, with a soft rubber that contours around your hand as more force / pressure is applied.  The handles are also very grippy, so your hands are not going to slide around them.  Flying a kite on the Flexifoil ProLink handles makes the kite itself feel a little smoother as the rubber is soft enough to take a little bit of the shock out as the kite is loaded up.  

Strop Connection
There is room at the back of the handle to loop your strop.  Simply pull out the pin from the top creating a gap, slide your strop in and push the pin back down.  When tightening the pin every few turns check that your strop is not being caught in the thread of the pin.  With the attachment for the strop designed this way it eliminates knots at the back of the handles which removes the hazard of the knots jamming in your pulley on a hard redirect.

Pin Insertion
The pin inside the handle is easily inserted or removed using a flat head screwdriver and accessing it from the top of the handle.  After using the handles a few times I noticed opening up the left handle the pin was noticeably looser then the handle on the right.  It may be worth putting a weak grade of nut lock / lock tight on the thread before you insert it to keep it firm.

Benefits of the design
One main benefit of the way Flexifoil have designed the new ProLink handle is how the power line leaders attach.  You can now easily replace your own leaders in your handles using either Flexifoil replacements or creating your own spliced leaders.  This is a real positive for people such as land boarders that attach 1m leaders to their handles to avoid wearing their lines on the edge of their landboards during grabs / tricks.  Something that started with Snowkiters and Kiteboarders wearing their lines on the edges of their boards.  You can now create your own leader, attach it and eliminate an unnecessary set of knots.  Buggiers are starting to use knotless leaders, you can now create a leader spliced at both ends, attach on end to your handle and loop the line on the other now removing all knots between your handles and the bridle of the kite.  Beneficial for those doing single handed moves and finding their lines catching on the knots coming off the handle leaders.

Safety Loops
There's a couple of loops on the back of the handle, personally when fastening a kite I tend to just loop the brakes lines around a peg in the ground.  However they are there to make it easier or attach safety devices such as kite killers.

Overall
With user-servicable parts such as leader lines and the attachment of the strop this means the life of the handles is extended.  The way the handles are designed also makes them far stronger then the old handles, so longer life out of them.  My conclusion is that you will wear out the grips on these handles before you ever break them!  Flexifoil have really put their thinking caps on with the new ProLink handles and eliminated some of the key things that have been issues with handles such as knots both on the back of the handle, and the leader lines.