I coined the name Bird mounts for these rear mounted Ravin crank handle holders years ago.  There are many advantages to locating the crank handle holder in the rear nearest to where it will be used.   And in fact, with Ravin’s introduction of their newer crossbows like the R5X/R10X and now the LR model, they obviously have agreed with that concept.
However, I was one of the few accessories designers would went even further years ago and designed my own  3 piece assembly that actually gripped the Ravin crank handle.  This is simply because I though the Ravin thumb button design was not only too stiff to operate but very inflexible in accommodating ambidextrous mounting functionality.
 
I’m pleased to say my Bird mounts have become extremely popular over the years and have literally taken me to where I am today with providing Ravin accessories to a larger audience.  I’m certainly not sure that this is a good thing as I’m getting older but it is what it is.
 
Bird mounts are available in 3 configurations as shown above.