This is the Arrma AR310402 Dog Bone 61.5mm (2pcs)

OVERVIEW:
These high-quality 60.5mm Dog Bones are manufactured from super-tough material for smooth and long-lasting performance.
Features: Strong and durable material for long-lasting performance - High-quality pins for smooth and consistent operation on all surfaces
Includes: 2 x Dog Bones per pack
Specification: 60.5mm Length - 2013 Update