Duragadget Cycle./ Bike / Bicycle Waterproof holder mount and case for GPS satnavs, fits all models including garmin Nuvi models 200w, Nuvi 205w, Nuvi 250w, Nuvi 255w, Nuvi 260w, Nuvi 265w, Nuvi 265wt, Nuvi 270w, Nuvi 600, Nuvi 610, Nuvi 650, Nuvi 660, Nu
This is a very nice, practical product that works well.  It's also very easy to install.  I'm looking forward to using it this summer.