The BlurFix3+ 55 Adapter, from SNAKE RIVER PROTOTYPING, is a 55mm filter adapter for the GoPro HERO3, HERO3+, and HERO4 standard underwater housing. It slips over the housing and leaves a completely sealed space between the housing and the filter. It can be used in three configurations: unsealed, sealed/air filled, and sealed/liquid filled. (Please see below for descriptions of the three.)
Three different-sized O-rings are included for sealing against a filter. They're compatible with most 55mm filters, including Tiffen CPL, Tiffen ND, Marumi CP, and Zeikos UV. (Zeikos CP and Rocketfish CP are not compatible.)
Reviews Snake River Prototyping BlurFix3+ 55 Adapter for HERO3/3+/4 Housing