Physically it would fit on to, but isn't compatible with, a standard lower.
The PDS lower is very, very similar to a regular LAR-15 lower, but there is no through-hole for the receiver extension to thread into. The PDS's lower is solid in the back because the recoil bumper attaches to that area of the lower. Originally the intent was to use an insert in a standard lower, but that didn't work out as the manner in which the system works will eventually damage the lower...it took a lot of rounds in testing to get there, but each test of several differently -equipped models all , eventually, damaged the lower.
We've come back to it several times, but each concept (so far) has had nearly identical results.
We do offer PDS SBRs as complete builds If that is of interest.
Steve/RRA