To anchor in your toy in that harness you need a good o-ring and the Tantus set of silicone o-rings that comes in this pack of 6 just what you need. Not only completely compatible with your Tantus Harness but also with most harnesses that take o-rings. The o-ring set of six will be able to lock in place toys with the following diameters: 1.2", 1.48", 1.74", 1.97", 2.22" and 2.5". Strap in, lock and load, and start pounding hard.