The new Rigit Kit from Mission Spec serves as an adapter that allows any PALS compatible surface accept the vertical male buckles and hook Velcro backing found on industry standard mountable chest rigs. The kit consists of six pieces that affix to columns of PALS webbing. Two of the pieces, referred to as Alpha Pieces, have ITW QASM buckles at the top and loop Velcro on their surface. The other four pieces, referred to as Bravo Pieces, have loop Velcro on their face.
Installation seems to be quite easy (see the video below). While this is shown in use with the Mission Spec Essentials Only Carrier (EOC), it should work with other carrier that have sufficient PALS coverage.
Check out the Rigit Kit at Mission Spec.