The Eden dual motor butterfly strap-on is not what my wife and I normally think of as a strap-on. The Butterfly strap on is designed for a woman to wear strapped on to herself for both vaginal and anal stimulation. It includes and small penis shaped section on the butterfly for vaginal insertion, the dragonfly tail is a vibrating set of anal beads and it includes a set of thigh and waist bands so that it can be strapped on and worn.

This dual motor butterfly is made out of TPR rubber which scores a 7 out of 10 on the Eden Safety scale. When we unpackaged it there was a slight rubber/plastic smells but it dissipated quickly and wasn't really anything more than you would expect when unpacking any new purchase.
The TPR has a soft-ish, flexible feel similar to high quality silicone.

The design of this dual motor butterfly is similar to most of the solo use butterfly toys on the market but it does have the addition of the vibrating anal bead tail. This tail was a nice enhancement from the previous butterfly my wife used.
Unfortunately there were a few downsides to the design of this toy. The wings of the butterfly are a bit too stiff so it's a bit uncomfortable to wear while standing or walking. In addition to the wings the penis shaped portion was too short to provide much stimulation and actually slipped out anytime my wife tried sitting down. These design issues make it difficult to use this as a toy to sneak a bit of stimulation while out in public.

This butterfly is controlled with a removable battery pack / control unit which consists of a singe button and a turn knob. The button cycles thru a selection of vibrating pulse patterns in addition to a steady vibration. The knob controls the speed or intensity of the vibrating motors located in the penis portion of the butterfly and at the end of the dragonfly tail.
Unfortunately the controls work for both vibrating motors at the same time so you can't have one speed/pulse vaginally with a different speed/pulse anally.

The Eden dual motor butterfly strap-on is made from TPR plastic and contains electric wires so it is not a toy you can fully sanitize. I would recommend washing, not submerging, with soap and warm water or spraying/wiping down with a specialized toy cleaner.
Because this does have an anal use portion and the inability to fully sanitize I wouldn't recommend sharing this toy with anyone else.