Brittany Birch Double Points. Most people use the shorter (5) needles for socks! The other sizes are 7.5 long.
Knitter's Pride Bamboo Double Pointed Needles is a similar needle: double point and US 15 (10.0mm) US size. You may also like Knitter's Pride Basix Normal Interchangeable Needle Tips Needles, which is another similar needle: us 15 (10.0mm) us size.
You may enjoy taking a look at the Blue Sky Fibers Bulky Mirrored-Cable Swing Coat, Blue Sky Fibers Bobbi Bear, Blue Sky Fibers Bulky Cardiff Coat, and Blue Sky Fibers Bulky Baby Hat kits all using Brittany Double Point Needles.