Waterproof fun bright nylon - easy Velcro on and off - lined with mesh and trimmed with reflective tape for visibility! Sizes measured at the chest: Tiny2 (for dogs up to 4lbs) 11-12", and Tiny3 (<6lbs) 12-14".
For sizing, you should check the specific chart referenced above, but you may find the following a helpful guide for a quick assessment ( inches refer roughly to length measurements):
Sizes measured at the chest: Tiny1 (2 lbs dogs) 10-11", Tiny2 (4 lbs dogs) 11-12", Tiny3 (6 lbs dogs) 12-14" and Tiny4 (8 lbs dogs) 14-16" XSmall 14-16" (<10lbs) Small 17-19" (< 15lbs), and Medium 20-24" (< 20lbs).
Lead is sold out in pink & yellow.