OMS 120 Maximum Depth Sticker A16918020 Marking Cylinders with a Label to Clearly Indicate Gas Content is an Essential Safety Component of Gas Blending for SCUBA Diving. OMS Produce a Large Range of Self Adhesive Highly Visible MOD � Maximum Operating Depth & Cylinder Contents Stickers designed to provide Additional Safety. MOD � Maximum Operating Depth 120 is just one of this Large Range.