Well.... I've just fitted my Jastek starter lead kit and I can only say that it does what it says on the can.
The engine spins over quicker, starts after fewer turns & there's none of that "wait for it, wait for it, I'm gonna spin it over in a mo' " type delay when the battery is seemingly struggling.
Went on nice & easy too.
A worthy upgrade methinks
Dead cheep too......
Andy