The F105W is what you graduate to after you realize the F-91W is essentially useless is the dark. I've worn both since the early 90s. The band always breaks bef

The F105W is what you graduate to after you realize the F-91W is essentially useless is the dark. I've worn both since the early 90s. The band always breaks before the battery or watch itself dies, but i still get a few years before the band breaks.