All the info about these laptimers is here
http://www.rollcentre.co.uk/ follow the link to laptimers.
Yep, you only need the lead to dowload to a PC or lap top, nice to do but not the end of the world if you can't.
The site has software downlaods as well if you do get hold of lead
Very easy to use, just make sure you have a new battery in it and take it out between uses.
Ray