Ultrasonic apertures set, with angle brackets

To carry out the following experiments on the subject of ultrasound:

US 07 Reflection
US 08 Absorption
US 09 Diffraction at a Barrier
US 10 Diffraction at a Single Slit
US 11 Diffraction at a Double Slit
US 12 Diffraction at a Circular Screen
US 13 Diffraction at a Disk
US 14 Diffraction at Fresnel Lenses
US 16 Lloyd’s Interference Pattern
US 18 Standing Waves Through Reflection
US 19 Wavelength – Speed of Sound

Set consisting of large apertures made of acrylic glass:
1 x Aperture entired
1 x Aperture semi
1 x Aperture with single slit
1 x Aperture with double slit
2 x 2 pcs. Fresnelapertures
1 x Aperture hole
1 x Aperture circular with shaft
these diaphragms are attached to the angle scale of the goniometer with a sturdy metal bracket and can therefore be swivelled and locked in place in a targeted manner
Dimensions of the apertures: 300 x 300 mm each
Mass: approx. 2200 g