hk5? Never heard of them, but it sounds like some shoddy eBay springs to me.
Though, I have heard that lowering springs on factory shocks/struts will reduce the lifespan of the shocks/struts by a whole lot. If you don't really give a shit, and bought these springs as something to fill the gap until you get coilovers, then by all means throw them on.
If you do care though, wait to put those on and do it right with some recommended shocks/struts (Tokico Blues, Koni Yellows, etc..).
