This is an elegant solution to measuring tension and needle size.
Made in Germany by Addi, it is white plastic with black printed measurements.
The edges of this frame carry holes for testing needle sizes. A measuring guide around the inside edge of the window allows measurement of stitches and rows over a 10cm (4 inch) area. This is the best measuring guide we have found and we use it in the store with customers daily, it is an invaluable tool for the serious knitter.