https://www.ebay.com/sch/i.html?_nkw=Allworx+8220001+Allworx+Px+6+2+Port+Expander+Includes+Internet+Call+Access+Key&_sacat=0&_dmd=2

Allworx - 8220001 - Allworx Px 6/2 Port Expander Includes Internet Call Access Key

Regular price
$1,570.00
Sale price
$1,170.00

Expand the capabilities of Connect systems with 6 FXO ports and 2 FXS ports each. Up to 3 Px6 FXO ports and 2 FXS ports each. Up to 3 Px expander units can be added to each Connect 731, expander units can be added to each Connect 731, 536, and 530 systems. 1 Px expander unit can be536, and 530 systems. 1 Px expander unit can be added to each Connect 324 and 320 to each Connect 324 and 320 systems.