I sold one before a while ago, a new old stock patch but unlike this one it was still uncut from the patch twill. This one came from the same collection that also had the  enamel badge for U-532 in it, shown on my pinterest page, yet I have no idea if and how these boats were connected through their crew. Do see last two images for its size and position when fitted on a side cap. 

Size: 5,5x4cm

Material: Brass

Material: brass

Size: approx. 4 x 1,5cm

ON HOLD

WWII Kriegsmarine U-Boat Cap Badge for the 2. U-Flottille, cast in resin.

The 2nd U-boat Flotilla, also known as the Saltzwedel Flotilla, was the second operational U-boat unit of the Kriegsmarine.

Materials: Aluminium + Lucite resin.

Lucite: the brand name for a clear acrylic resin (polymethyl methacrylate), is nearly 90 years old, developed by DuPont in the 1930s (invented 1931/1937) and first widely used during WWII for aircraft canopies, becoming a popular material for fashion accessories and furniture from the 1940s onward. 

Dimensions: 5,5 x 4,5 x 0,5 cm