I bought one for $4 from meritline 4 years ago. I have 18,000 miles on it and everything I want (distance, time, speed) still works. The average speed now only reads multiples of 1.8 mph (truncated to nearest integer multiple below actual); for a while it read wacky maximum speeds (78, 87 mph), but I don't care about either of those. The cadence always looks correct. The clock gains about a minute per week - 1 part in 10,000 - which isn't very good for a clock (I reset it every few months) but I don't need time that accurate when riding. I cracked the bezel when I forgot to remove it when I turned the bike over to repair a tube so rain gets in and puts it on the fritz, but I take out the battery and let it dry out overnight and it works. I'm glad I didn't spend big money. No heartbeat/glucose/blood pressure/ventilation rate/insulin/body temperature/barometer...