In 1984, Tom O'Hanlan designed the first RS-422/485 communication adapter for the IBM PC. From that moment of inspiration, Tom and his wife Susan saw an ever-growing industry-wide need - and began work to fulfill it. In 1986, they formed Sealevel Systems, Inc. committed to providing reliable, well-designed communication adapters for the IBM PC and compatibles.
More than 20 years later, Sealevel continues to provide innovative, reliable hardware and software products to enable computer connectivity and control. Today, we manufacture more than 300 standard I/O products with ISO 9001: 2000 registration and a standard lifetime warranty.