The Gymshark metal shakers typically feature:

1. Material: High-quality Stainless Steel (often 100% steel for the body).

2. Capacity: Common sizes are 600ml (or about 20oz) and 740ml (or about 25oz).

3.  Mechanism: They often come with either a metal shaker ball or a built-in mixer/net thing in the lid to help break down powder clumps for a smooth mix.

4. Design: They usually have a sleek, modern look with the Gymshark logo, often in a polished or matte finish.
5. Lid: They are generally designed with a secure, screw-on, leak-proof lid.
6. Care: They are typically hand-wash only and not microwave safe.