A holder serves as a removable accessory to a stimulator unit chassis or cabinet, or other device. It can function as an integral part of the device that closely fits over the top of the device, to provide a support for a hand-held tool associated with the device, e.g., a bipolar probe with widely spaced electrodes. The holder, which may be constructed to be of one piece, is configured to be easily removed from the device to facilitate cleaning of the holder and/or to facilitate packing of the stimulator unit (or other device) for shipping purposes, e.g., in case of device repairs, etc. In other embodiments, the holder may associate a tray or box for storing a variety of items with a host device on which the holder is mounted.