Indoor ventilation vents for a condominium. These are Nasta indoor ventilation vents. KS-8830PR-SG SU100 (inner diameter Φ100) x 3 KS-8630PR-SG Kyowa 150 x 2 This is the set. I think it's a very affordable price. I took one set of each out of the bag and lightly tested them, so they have been removed from their packaging. Please purchase if you understand this. I bought them, but the size didn't fit, so I'm selling them. They are unused and have never been used. I will sell them at a low price to someone who uses Nasta ventilation vents! I will ship them in a box. I have put them in the ventilation vents, but I have not used them for ventilation, so they are listed as "like new". You can easily remove and replace old ventilation vents!