Lewmar Medium Profil Hatch Size 30 Flange Base Hatch. Product Description: Utilising thicker acrylic and deeper frame sections, the medium profile hatch provides greater strength and durability whilst echoing the sleek styling of the Low Profile hatches. It is ideal as a foredeck hatch on larger offshore yachts. The hatch also features Lewmars unique sealing system allowing easy acrylic replacement. All sizes suitable for CE Area 2 (Deck, Coachroof, Cockpit and Transom). Mounting Instructions: Fit to a flat surface with a maximum tolerance of +/- 1mm. Fastening size at hinge section use (M6 / 1/4"). Fastening size for lower frame use 5mm CSK screw No.10 UNC 2 BA.