SHOP ONLINE › Adjustable Ring Sizer Image 1 of 3 Image 2 of 3 Image 3 of 3 Adjustable Ring Sizer $2.00 Multi-size adjustable finger gauge is ideal for determining ring size, and measures U.S. sizes 1–17 in half-size increments. Quantity: Add To Cart Added! Multi-size adjustable finger gauge is ideal for determining ring size, and measures U.S. sizes 1–17 in half-size increments.