Originally Posted by
Onebyone
That is the original purpose of the Slidelock to be on top of your ruler. Not on the cutting edge of the ruler but to hold your ruler in place. It use to be called RULE STEADY. I have one of the first ones from Australia and one of the newer ones. They are both exactly alike.
The rule steady is totally different. It sits partly on and partly off the ruler so it does hold the ruler steady. The slidelock is just a flat piece of plastic with a handle and some rubber balls.
http://rulesteady.com/product/rulesteady/