He following products have been confirmed to be used with the Olympus TG-6 camera in the waterproof case PT-059.

Compatible strobes
The YS-03, the YS-01 and the YS-D2. * Works with the original firmware.

Compatible Wide-angle conversion lens
Product # 52151 M52 Wide-angle conversion lens WCL06

Relatively compact wide-angle conversion lens. Can be attached to the waterproof case without any conversion ring.

Vignetting may occur when the zoom lens is set to the most wide-angle position. Zooming slightly may be required to avoid it.