April 30, 2019 by $245.00 MEM2 16Mb of RAM, internal MEM2 - Extended Memory Upgrade for PS4550/PS3550 quantity Add to cart Category: Accessories Related products TH-USB – Temperature Humidity Logger $125.00 Add to cart BTA – Bluetooth USB Adapter $45.00 Add to cart USB-COMM – USB Communications Cable 6 ft. $30.00 Add to cart CHG4 – 120V Wall Charger (for all but PS3000) $20.00 Add to cart