Pure Stainless Steel. Insertable length 60mm, diameter varies between 5-7mm. 

One picture has complete measurements, one is next to standard #2 pen for size perspective.

NO electrical connection present, but can be easily added with items from our Do-It-Yourself section. A small pad or gator clip is the simplest. For other how-to ideas and instructions, check out the forums at smartstim.com.