The Men’s Round-Neck Sleeveless Knit Vest is photographed in Khaki over a white collared shirt. Grey and Black are also current options, with sizes S through 5XL. The chart has columns for shoulder, bust, “Collar” and length. That collar number looks precise, but the page does not define whether it measures a flat opening, a circumference or another point. It should not be treated as a neck-size recommendation without that definition.

Choose the body fit before the neckline

Across the eight listed sizes, bust runs from 117 cm at S to 152 cm at 5XL; shoulder width from 45.5 to 56 cm; and length from 71 to 78 cm. Each size step adds 5 cm at the bust, 1.5 cm at the shoulder and 1 cm in length. The “Collar” row rises only 0.5 cm per step, from 21 to 24.5 cm. Moving up several sizes to solve a neckline concern could therefore add much more width to the body than to the unspecified collar dimension. Measure a vest you already like at the chest and shoulder, then compare those garment values with this chart. The garment-measurement guide explains why a listed bust value is not the same as your body circumference.

Test a collared shirt as an underlayer

The Khaki gallery image shows a white shirt collar rising above the vest’s round neck. If that is the look you want, put the shirt you plan to wear under a sleeveless vest you own. Check whether the collar lies flat at the front, whether the shirt bunches at the shoulders, and whether the armholes leave room when you reach forward. Then repeat with a thinner or thicker shirt if both are in your wardrobe. This is a fitting exercise with your own clothes, not evidence that the MAXCT vest has been wear tested with them. The listing does not give armhole width or an underarm depth, so ask for those measurements if you need a close layered fit.

Do not convert the collar figure into a neck size

A 21 cm chart entry at S is not necessarily a 21 cm neck circumference. Without the measurement path, doubling it or comparing it directly with a shirt’s neck label would be guesswork. Ask the seller for a photograph of the collar measured flat, with the tape’s start and end points visible, if the opening is important to you. Check the same points on your reference vest. The product lists 100% polyester and a manual-measurement tolerance of about 2 cm; it does not specify knit thickness, care directions or stretch recovery. Use the gallery for the shirt-and-vest styling idea, the chart for clearly named garment dimensions, and a clarified collar/armhole measurement before relying on the opening for fit.