A manual tool change spindle just has a collet nut.
HSK tooholders only work in ATC spindles. You can use an ATC spindle manually, but it's still an ATC spindle. So, you still need to pay the very high ATC spindle price
I've never seen an Elte, but have used HSD ATC spindles in manual mode. You just push a button on the spindle to release the toolholder. To insert a tool, push and hold the button, insert toolholder, and release button.
This would be a manual too change spindle, where the collet nut screws on to the end of the spindle shaft.
70067_SER: 3hp TMPE3 12/2 ELTE Spindle-220V CNCRouterShop.com
An ATC spindle has a recess for the toolholder, like this:
22104: 5hp (3.8 kW) HSD ES915 QR Spindle CNCRouterShop.com