WOW!! These hooks are to BEAUTIFUL to describe! The picture does not do it justice. There is no need to buy a D Ring to use with this attachment as the D Ring is also part of the hardware. On one of the D Rings there is a squeeze connector that reminds me of a clothespin. You squeeze it open, and place the other D Ring into the connector attachment for a secure hold. What a great 2 in 1 piece of hardware! They are sold as a set of 4 of the same finish. Available in Nickel, Rose Gold,Gold, Gunmetal. Brushed Nickel and Brushed Gold. The inside diameter for your strap is a perfect 1 1/2", making the Butterfly total width 2 1/4"