Series L1B utilizes wall mounted standoffs while Series L1D utilizes both wall mounted standoffs and floor attachments. Aluminum ladders are used in both above and below ground applications where corrosion resistance is required. Ladders are of welded construction and utilize 1/2" x 2 3/4" (13mm x 70mm) channel stringers with 1 3/8" (35mm) diameter type "D" rungs with flat slip resistant surface. Standard ladders are 16" (406mm) wide. Standard stand off brackets are 7". ***Two Week Lead Time***