Replacing TENS electrode pads can be confusing, especially if purchasing for a secondhand Tens machine. Electrode pads come in a variety of sizes, shapes, connections and quality. The size and shape of the Tens pad will be determined by personal preference and their suitability to the part of the body for which they will be used. For example, large rectangular Tens pads are ideally suited to treat large areas of the body such as the back, abdomen and thigh; the smaller round pads are more suited to treat areas of the face or more tricky areas such as the knee or elbow. The square electrode pad is the most common shape of Tens electrode pad and probably the most versatile, it can be used appropriately on almost any area of the body and is more suitable for targetting specific pain points compared to the larger pads.
There are generally two types of connection, the prewired electrode pads or stud pads. The prewired electrodes, sometimes referred to as pigtail electrodes as they have wires attached connect to Tens lead wires with pin connectors on the end. These are nearly always a standard 2mm pin connection which slot into the wires on the Tens electrode pads.
If your Tens lead has a snap connection on the end, then this can be more complicated as unfortunately the electrodes with stud connections have different sizes of stud. This is especially problematic if you have purchased a secondhand machine and you do not have any original pads for reference. However if you know the make and model of the machine a quick search on Google may prove advantageous. There are many You Tube videos posted by helpful Tens users as well as links to forums and useful websites.