The LA-401/LA-401BA comes with four stand offs and mounting hardware. 1″ diameter ladder tubing. CAUTION: All screws connecting the ladder to the RV must be fastened to the RV’s sub frame or backing. If you are uncertain if your RV has backing installed, contact your RV manufacturer to confirm. It is unsafe to use a ladder that is not connected to the RV’s backing or sub frame. Please note: To maintain the recommended 12″ spacing between treads, ladder must be trimmed to 92.5″ as shown in the Ladder Dimensions image. If you wish to utilize the additional 15″ of upright tubing provided, you will need to purchase an additional tread.