[SIZE]: - Fits 1-1/2" (1.5) OD 38MM square tubing (1.5x1.5) with INSIDE hole diameters (ID) from 1 1/4" to 1 7/16" and wall thickness of .040" - .122" (10-20) Gauge | [FUNCTIONS]: - Reduce noise, prevents scratching of your floor surface and protects your expensive furniture when furniture is moved. These tube plugs are also nice dress up for the ends of the gorilla lift square tubes, fitness equipment end caps, fencing post end caps, furniture gliding caps, and prevent the rain to come in and rust out the spring. | [APPLICATION]: - These high-grade black ribbed plugs work great for preventing scuffs on wood floor or as protection glides on chair tips, bench feet, table legs, bar stool foot sliders, chair leg protectors, patio furniture inserts, and much more. They are also designed to hold up against impact abuse, and harsh weather conditions. | [PREMIUM QUALITY]: - Made by high Grade heavy duty black polyethylene, UV weather resistant and long lifetime. Features a series of tapered ribs which ensures a secure fit perfect for use on a wide range of metal furniture, appliances and similar items. | [SATISFACTION GUARANTEE]: - We stand by our quality commitment and will guarantee you 100% satisfaction of the fretboard protector. Please do not hesitate to contact us if there is any question. We will do our best to solve the problem as soon as possible.