Slideout jacks

[dlott84040]

Did a search on Slideout jacks and didn't come up with a answer. Thinking about buying a set of slideout jacks for the dining area slideout and wondered if this were necessary? I feel leaving the slideout out for an extended period of time could be harmful for the rig. Is this true and does the jacks provide enough support for the sideout to remain extended indefinately? Although the kitchen slideout doesn't extend very far the weight is far greater that the other sides and there for does that slideout require support if you leave them out for long periods of time. Just trying to do what is wise but not throw a my money away for useless things. Thanks, Doug and Becky