The Ripple Small is a great first plug. 

Its graduated design is starter size - smaller than a finger tip to start, and 1" across at the widest point.

Safe For Your Body: Made from Tantus’ own unique formula of 100% Ultra-Premium Silicone

Easy To Clean: Eco-Friendly, Hypoallergenic, Hygienic, Boilable, Bleachable and Dishwasher Safe.

Diameter: 1"
Length: 4.95"