Ideal for laying on fronts airline preassembled or concentric, are composed of a block of insulating material providing support expansion lug by the action steel nail. are available suitable models for drivers to beam 25 and 50 mm diameter, fixed through seals including plastics.

Beam diameter Drivers	Seals	Perforating by depth
To 25 mm	1	Φ 8 x 38 mm
To 2 x 25 mm	2	Φ  8 x 38 mm
To 50 mm	1	Φ  12 x 65 mm
To 2 x 50 mm	2	Φ  12 x 65 mm