Here is a yellow plastic alarm clock by Seth Thomas called Minicube. The clock is given catalog number 557 and model E043-000. Seth Thomas is a division of General Time, a Talley Industries Company. The clock is approximately 3-3/4” on a side. It operates on AC and must be plugged in, it is not battery operated. On the label is stamped “8 77”, probably indicating a manufacture date of August, 1977.
eBay item 140897196400 ends December 16, 2012 at 16:04:39 PST (United States).