I recommend you read the negative reviews first. If you have carpet in and in front of the slide, these are NOT for you. The slide outs are supposed to “float” over the floor, except the rollers if you have them, and why you are NOT supposed to be sitting in or using a slide that has been retracted. Check the flex in the middle of the slide floor. There is not enough support to hold much weight when retracted. This is especially true for large slides. For bare floors, they might work but folks with bare floors have had issues also. So to me it looks like a crap shoot. I would try the least expensive method first. The Lippert brand are near $75 from Amazon and folks have had issues trying to return them. Amazon has a warning that they are a frequently returned item. Buyer beware.