Got the new 25" locking flex ratchet, pn R12LFL120, yesterday, but only had a few minutes to play around with it.
As far as head dimensions, I took 2 quick measurements:
- Head width = 1-1/2"
- Head thickness = 3/4"
For reference, the Powerbuilt Pro Tech 1/2" 72T flex head, pn 649956 (which I've read here is the same as the older Carlyle), is listed online as 1-1/4" wide.
The new Gearwrench 120XP locking flex head, pn 81376, is listed online as 1.449" wide, 0.685" thick.
Snap-On's equivalent dual 80, pn SHLX80A, is listed as 1-5/8" wide, 3/4" thick.
I've only ever used non-locking flex heads, but the flex in unlocked position on this ratchet was pretty wobbly out of the box, so I'll see if tightening the pin gets it closer to what I'm used to. With the flex head locked, there's still play but that seems typical of locking flexes. I was also expecting the backdrag to be quite high, similar to what others have stated about dual pawl fine-tooth ratchets (e.g. 120XP), so I was surprised that it was reasonably low. Nothing quantitative, but this is comparing against 1/2" drive coarse-tooth ratchets I have - a RP USA Craftsman with high backdrag and a very low backdrag 30-tooth Ko-ken.
I'll have to do a follow-up post once I've had a bit more time with it and include some pictures.
EDIT: add part numbers