This is an Australian made product.
Simply place the bike wheels in the channel provided which also stops the handle bars flapping around,
Put the U hook over the top tube and use the ratchet tie down to secure the bike.
Takes no time at all.
We usually carry our Thorn Tandem but we have carried my wife's Bike Friday which does not have a top tube so we have to wrap the ratchet tie down round the frame a few times to shorten it.
This bit of kit is about 60% of the cost of comparable Thule models although it does not look as elegant and the Thule cannot accommodate our tandem.
https://www.gripsport.com.au/product/2-bike-hi-ride-fixie/
Mike