*** IN STOCK SHPS TODAY *** Here is a nice simple way to check the rod bolt stretch when doing connecting rod maintenance on your race engine. When getting ready to install your rod bolts simply slide rod bolt into the fixture, record a measurement and when doing the next engine maintenance check again and sort out the rod bolts that have stretched beyond there use cycle. A very helpful tool with a very easy to read dial indicator. Tool is designed for 7/16" rod bolts.