Arkon HD003-AMPS Heavy-Duty Drill-Base Mount with 22 inch Arm - 4-Hole AMPS Compatible (sku 55991)22 adjustable arm and swivel ball provide flexibility in positioning device Compatible with devices and holders having a 4 Hole AMPS pattern Drill base recommended for permanent installations The HD003 AMPS Drill Base Mount with 22 inch Adjustable Arm is compatible with Arkons Slim Grip Universal Tablet Holder (Model TAB001 AMPS), as well as other 4 Hole AMPS compatible adapters and components (sold separately). It is also compatible with devices