120x Custom Cherry MX Springs (3-Pack)

If your switches are PCB mounted without a plate holding them in, then yes this is true. If there is a plate, you can only open the switches if there are cut outs on the left and right of the switch. You may also only open gateron or cherry switches this way. Kailh and Outemu switches cannot be opened while soldered to a board. They have a different closing clip from the Gats and Cherry's. It is possible sometimes to force a switch open accidentally, but you will have a very hard time putting it back in if you have a plate. The only 100% guaranteed way to open a switch on a plate mount is to desolder it from the PCB first.

This is a great deal for anyone wanting to experiment with different springs. I just signed up for two orders, getting all six weights.

if you already know you're able to open up your switches without desoldering them, you'll be fine. Not all top plates allow this, and in those kinds of keyboards you would have to desolder the switches.