Below is a review I posted of the RRS series 2 apex conversion kit I purchased so I could mount a QD strap to my 24L tripod I purchased in 2015.
The Apex conversion kit is said to be for series 2 tripods purchased before 2016 which don't have the holes in the apex to mount the apex QD mount. I purchased a 24L tripod in mid 2015 so assumed this product would be what I needed. Well it doesnt fit my tripod legs, this apex is 0.7mm bigger than my old apex which is already an extremely tight fit. Contacting support I was told if it doesn't fit then its not compatible, thanks for stating the obvious but this isnt listed anywhere. There must be an incredible small window of time that this product would be compatible unless I was shipped an old tripod when I purchased my tripod. This has left a very sour taste in my mouth.