Not sure if this is a good deal.
Oral-B Precision Clean Brush Heads (5 Pack) is $19.65 on the web site.
I was able to get a bonus Oral-B Pro 100 electric toothbrush handle for free at Woolworths Rhodes for free (worth $17.50).
Please note that the price of electric toothbrush is marked as $17.50 but you get it for free if you purchase the toothbrush head pack.
I have uploaded my receipt here to make it clear.
Looks like the deal is only available in store. This deal is similar to the previous Coles deal but in Woolworths, it's free with 5 pack brush head.