I have an older Cateye Micro Wireless Cylclocomputer Model MC-100W. It's probably 6 or 7 years old and still going strong. Nothing fancy about it. It has Current Speed, Average Speed, Max Speed. Odometer. Trip Distance 1 & 2 ( if you wish to use it on two different bikes ). Elapsed Time. Choice of 12/24hr Clock. Night light. I believe the cost was about $40 new. Similar Cateye computers now will run from $50 tp $65. The batteries, one in the sending unit and one in the receiving unit will last for a couple of years. Both are CR 2032 size flat cell type batteries. It has been a very good accessory over the years with nary a problem. You may be able to find a cheaper unit if these type have more functions than you want, but the units you find a Kmart or Walmart type stores will cost about $15 to $25 these days, and are likely to need replaced after a one or two years. I prefer wireless over wired for the somple reason that wires can be a hassle to route and keep nice looking.