Both hoses are in compliance with applicable FDA requirements meeting NSF 51+ 61 certified materials. The only difference between the two is that the K3130 Series has a larger wall thickness and a higher pressure rating than the K3150 Series.
Amazon stocks sizes from 1/8 inch inside diameter up to a 2inch inside diameter. Metric sizes are not stocked, but can be ordered in the K3150 Series.
As always, AH&R will sell and assemble lengths of both hoses with appropriate hose ends that apply to your application. Please contact your local Amazon Hose & Rubber sales office today in Orlando, Tampa, or Miami to find the right hose for your application.