This is a new MackBeth Whistle, #15, a tunable brass high D model with white plastic head and white fipple plug. It is slightly louder than many MackBeths due to the larger window and its best uses would be for session, solo performance, or standard practice.
This whistle has a small backpressure feeling in the second octave. It has low air requirements so good breath control is important. The best C natural fingering is OXXXOX followed by OXXOOO as a second choice. It is a little less prone to condensation clogging in colder areas due to having a plastic headpiece.
Purchasing this whistle qualifies your Sheepshape order for free shipping within the US.