Man suspenders refers to a pair of suspenders used to keep up worker clothes such as construction pants suspended. (Hence, the name, suspender). A regular pair of suspenders is designed for the purpose of keeping a pair of pants held up and avoiding the bunching that happens when a belt is tied very tight. A suspender takes on the doubly difficult task of being affixed to pants that regular suspenders will never be able to hold up.
It is not because of the worker pants being overly heavy. Although the fabric may be slightly thicker than standard jeans, the thickness of the pants material is not what is too heavy for standard suspenders to hold. The reason is that the pants that a suspender is attached to usually have several tools attached to the pants directly. Hammers, saws, tape measures, screwdrivers all add several pounds of weight to the workman pants. The suspender must be able to hold the weight of all these added devices and keep the pants in place. Not an easy task for the man suspender.
However, a quality man suspender has the ability to do this task quite fine. The person wearing the man suspender and the attached tools should be able to spend the entire workday without any worries or hassles of having to readjust his tanks. In some situations, this could create a safety hazard. In that regard, a good suspender set is a totally indispensable clothing accessory to purchase.