Type: Two-piece whistle - not telescoping, but detaches in the center.
Volume: Quiet with a small amount of backpressure.
Status: Undergoing work to try to resolve wobble at the joint, which seems to vary substantially with temperature. May sell as a prototype model for a discount if there is interest.
Additional details: This whistle will fit in a travel case. The length of the longer section is just under 6.5 inches. The mouthpiece is white plastic with a green plastic plug.