The Groove is made of "Platinum Premium Silicone". The silicone is a lovely medium firmness the bumps at the thinner portion of the top of the toy are more flexible than the base. It has a lovely matte texture which lube loves to cling to. The Grove is available in blue and charcoal gray, both are highly pearlized and sparkly.
The Groove starts off a little thicker than my pointer finger and gradually "bumps up" to a circumference of around 4 1/2 inches. The tapered increase occurs over the 6 inches insertable length of the toy making it a smooth and gradual stretch. The smaller spaces between each bump allow the muscles to relax a little before the next stretch.
The matte texture of the toy holds onto your lube of choice while still providing a nice bit of drag. The length of the toy is manageable and the slow progression in size makes this the ideal toy for someone who is relatively new to playing with their butt and looking to step up a bit.
My only caveats with the greatness of this toy are that it tends to retain the "scent of butt" despite soap and water and a bleach solution wipe down. The other issue I had was with the small Doc Johnson logo stamped into the base of the toy, it filled with lube and "stuff" and was a real pain to scrub out.
Never use silicone lube with silicone toys. Always spot test lubes with silicone composites(like dimethylcone) in them in an inconspicuous spot on your toy to check for compatibility, we used Liquid Silk to no ill effect.
Easy to clean with soap and water, toy wipes or sprays. The groove is also top-rack dishwasher safe.
The groove can be sanitized in boiling water or with a 10% bleach solution.
It comes in a sturdy but easy to open plastic molded clamshell package with classy scroll work graphic. It's not even remotely discreet, but it's better than the standard issue "moaning chick with bedroom eyes" most toys have. The packaging can be used for storage, but I find it to be rather bulky.