Wanhao Duplicator 4 bed level jig - Works with Replicator, CTC and other brands as well

If you have ever been frustrated with the bed leveling procedure on your printer, this is for you :)

A small clip-on piece that lets you use a dial/digital indicator to level your bed with ease.

Center hole is just under 8mm in diameter to make a really tight fit with the indicator.
I use this indicator, but you can use different ones as well:
http://www.ebay.com/itm/221959185150?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Use any 12mm diameter magnets and press them through enough to not touch the rods. That way it will slide with almost no force.