The wand can be inserted anally or vaginally for estim purposes. This is a good size for most people. It's only about an inch wide, so beginners should find it easy to insert. Size queens might want more girth, but this is a pretty good universal size and I don't think for the purpose or use that girth is the most important factor.

The current from the estim control box causes contracting/tingling sensations in the interior regions (prostate, rectum, anus). Results may vary based on amount of lube, depth of insertion and sensitivity of the individual. I believe they can be used as kegel exerciser too. Suitable for solo or partner play, but just be sure you've tried it before you hand the controls over to someone else. It takes some warming up to initially.

The control box is required.

The material is an aluminum alloy metal, designed as a probe with bulbs for extra stimulation. It's of course firm and maintains heat/cold, before warming up to body temperature for Temp play. It's smooth to the touch and shiny. A good size for beginner and intermediate users. Very comfortable to insert and stays put.

The tingle e-stim wand is 6 1/4" long, 1" in diameter and is insertable to about 6", but you only need to insert it to where you like it. It weighs a hefty 7oz.
It is a phallic shape, but has bulbs for added texture. It's a nice shape for insertion with a round tip.

The probe itself has no moving parts. The current from the control box causes stimulation of the skin/muscle/tissue inside the anus or vagina. The metal conducts quite well and is very comfortable to insert. Operation is silent.

The bulk of the sensations come from the tip of the probe, so I found it optimal to only insert it a few inches. It inserts deeply and feels comfortable probing myself, but for the electro sensations my happy spot is only 2-3 inches inside. The probe is an optimal size for me. 1" width/girth is easy to insert and feels comfortable and it slides in/out easily without pain or discomfort.

You can clean with 10% bleach solution, toy cleaner or soap and water. Metal is easy to care for as it is non porous and durable. There is a little piece of plastic/rubber near the tip, but nothing to worry about care wise. It does however give a little crevice for fecal matter to collect, so you will need to be more diligent cleaning that area. Same for the nobs. It might be a good idea to douche before use.

Minimal, but comes with a storage pouch, which is nice.

Suggestions:
Relax and be aroused prior to use
Use water-based lube only
Insert lubed toy before plugging in and turning on control box
Might want to consider douching if using anally for optimal performance and cleanliness.
Start on the tap setting and find the strength that feels best before jumping to other modes
Experiment with inserting probe at different depths to find that sweet spot (deeper not always better)

The first time I tried using this, I found the stimulation at the lowest setting unsettling. I wasn't ready to turn up the knob or try another mode. I think I was just not ready for it and inserted the probe too deep. I tried again a few days later, this time inserting just a few inches. At first It was the same. I wasn't crazy about the sensations, but it wasn't painful. Just weird. I decided to relax for a bit and move the probe around and find the magic spot. Eventually I found myself comfortable with the tap and had it inserted no more than probably 2", I was ready for the other modes. It took a little experimenting and shifting, but I found a pleasure zone and was enjoying vibration/massage modes at full power. It only took one or two of the first waves on massage on my prostate area that I knew I wanted to feel it at a higher setting..but I moved it up gradually to be safe. It was quite an interesting sensation. Being fully aroused helps and I even found that keeping it on after cumming felt good as I gradually slid down into resolution phase.

It's hard to describe the sensation...kind of like being fingered, but with a finger that is electrified. You can feel it on your prostate and internal areas. I need more playtime, but I'd say douching would probably enhance everything. I will report back on my follow up review. All in all, after initial disappointment, I am happy with this toy and will keep using it. It's not entirely different than a vibrating probe sensation-wise, but it's still a unique feeling.

The only minor issue is if you insert it a few inches you may need to put a finger on the end to keep it in that spot or lay on a towel such that the probe sticking out has something to keep it from sliding out. Luckily having two hands is enough. I would definitely like to try this with partner play. I'd say if you like anal vibrators, you will enjoy this probe.