Product Overview
Splicing dog bone. - Black Colour
Max outer diameter: 10mm
Length: 36mm
Min inner diameter: 6.5mm
Rope diameter: 5mm-6mm
Lacing eye: 3.5mm
Safe Working Load: 900kg
Breaking Load: 1800kg
Weight: 4.6g

how to see : https://www.allenbrothers.co.uk/2022/01/13/how-to-use-sailing-dog-bones/
These are spliced in a rope end and used to hold similar to a stopper knot or Diamond knot.