Spire GigaPod CF103-NEB ( 3.5 " External Drive Enclosure )
Product Page

Prolific - PL2507/3507 Windows 98 Disk Removal Utility V1.4.0.0
WebPage and Main
Direct link to installation file

Local mirror:
Installation file
Installation and usage manual
Windows 98 Second Edition 1394 Storage Supplement
Prolific Webpage->Drivers->PL3507Combo