As with many of Doc Johnson's similar plugs, the Triple Ripple is made of Silagel, which is a rubber blend. It's a decent, sturdy and very large **** toy that I found really useful for one thing. This is a toy I use for stretching my ***, to put it simply. Due to the design of the plug, it doesn't stay in well at all, but rather pops right out, unless I am sitting on it, or have my partner holding it in place. However, since it is a larger toy, it does the job of stretching quite well!
The Triple Ripple has a slick outer layer, with a softer more flexible core. This gives the whole plug a bit of flexibility and makes the size slightly less daunting. Slightly. This is still not a beginner sized toy as maximum diameter on this toy is 2-3/8".
Being rubber, it's compatible with H20 based and silicone based lubricants, but not oil as it can degrade the material. Also, since it's rubber it definitely has a smell. This doesn't bother me at all since I really like the smell of rubber, but those with sensitive noses may be bothered by this. I have found the smell does diminish somewhat over time, just not completely. You can wash it with regular/antibacterial soap and hot water, or use toy wipes/spray for cleaning.
A definite plus about this toy is, the price. It's very affordable, so if you are in need of a larger toy (particularly for '**** training' or warm-up) and don't want something too spendy, it's a good pick.