The manufacturer states that the JP Enterprises MK III Modular Handguard Signature Series for the DPMS LR-308 is full compatible DMPS LR308 pattern rifles. They do not specify if it is high or low tang or designed to fit both. For that information I recommend contacting JP Enterprises. However, the Aero Precision M5E1 upper is set up to only accept Aero Precision M5E1 handguards.
This a guard has no 1913 top rail so it’s not applicable. It will fit both high and low receivers, I’m guessing they offer a removable top rail piece that will match up to the DPMS gen 1 (hight) The hanguard it’s self will work on a high or a low without the top rail piece, that I’m sure they sell. Precision reflex sells a handrail just like this that does have the top rail piece to match up with DPMS high tang receivers.
I called JP, and they said these are "high". Hope this helps. Call JP if you need further help. They are more than helpful.