Ishi Sashi, or stone padlocks, were originally the locks used on Okinawan doors. When removed they also make excellent tools for developing grip, shoulder, and wrist strength necessary for martial arts. Tools similar are found in many other cultures, the most popular being the Russian kettlebell. Ishi Sashi are traditionally used in pairs and in a wide variety of exercises. 

Made of concrete

15lb (6.8kg)each

sold in pairs

As with any small molded concrete item small cracks and chips are common and perfectly safe. These are handmade items so each one is unique.  

Please contact me if you have any questions. The ishi sashi is part of a whole line Hojo Undo equipment I make including standard and olympic weight sized chi ishi handles, nigiri game (gripping jars), makiwara (striking posts), and even kongoken.