Unfortunately, we do not have a BBG that fits the ME 66 due to the length of the mic's slots. The best alternatives as slip-on solutions are the 18cm Classic-Softie® (19/22) and 18cm Super-Softie® (19/22).
Additional info and order code for the 18cm Classic-Softie:
Additional info and order code for the 18cm Super-Softie:
Each Softie has a diameter indicator in brackets after the product title. For example, 18cm Classic-Softie (19/22). This indicates the microphone diameter that each Softie will accommodate, based on internal bore size: a 19/22 model will accommodate mics with a diameter ranging from 19mm to 22mm, and a 24/25 model will accommodate mics with a diameter ranging from 24mm to 25mm.
Please note that the 18cm Classic-Softie (19/22) also comes in the form of a kit, which includes an InVision Softie Lyre Mount with Pistol Grip, high-quality Neutrik XLR cable, and the Softie itself: