First of all, I'd like to say wow, with the two holders and 4 weights, the combinations are endless. I figured out there's a total of 7 weight combinations. From single 30 grams to, if you use all three like I just tried, 110 grams! I got these on sale and was looking to get back into Kegels. I've had bad experiences with ben wa balls before (they got lost), but after doing some research, I decided the price was right, and the set seemed the most user friendly. It wasn't til I just got them that I realized how good of a set they truly are.
I thought the anchor point in the middle would be stiff; it's not, it's very flexible and has a lot of give.
They're very beginner-friendly, and I'd say the only set you'll ever need unless you want to go really heavy or non-silicone. I wanted a very comprehensive set, one I could buy and probably never need to look at other sets again (though I do want a vibe one). The balls have the weights on them to! So you'll never get them mixed up. (Like pussy dumbells)
The weights break down is as follows
30g
40g
50g (30&40)
60g (30&30)
80g (40&40)
100g (30 30 &40)
110 (40 40 & 30)
And if you're crazy and want A LOT of weight, you can use all 4 of course.
Now, the vibes. To start out, I used one single 30 with its holder, and I can honestly say at first I didn't notice, I took a shower, did the dishes. Then I sat down and started squeezing, just to see if I could feel anything. The ball moved (I'm in my late 20s, no kids) up, and when I stood after doing 30 Kegels, I felt it vibrating way up there somewhere when I started to walk out of my living room. I tried the other 30 with it on the double holder, and I was impressed! I thought the vibes wouldn't be that strong, but I could definitely feel them! Expectations exceeded!
The size is good; the larger balls are about 1 3/8th, so a little under half by my caliber. The small ones are 1 1/4th. Not much of a size difference. But from my research it's not about size, it's about weight. The bigger they are, the easier to hold anyway, but it's a work out it's not supposed to be easy.
Oh, and they are making me wet, so there's that.