Hi Kevin
Thanks for contacting the Answer Army to post your questions.
That machine is designed to hold the keyed type blades (the lower picture) This helps to keep the blades from spinning loosely and causing the blade lock nut to back out and throw the blade.
I hope this answers your question.
Thanks again from the Husqvarna Technical Services Team.
Hi Kevin
Thanks for contacting the Answer Army to post your questions.
That machine is designed to hold the keyed type blades (the lower picture) This helps to keep the blades from spinning loosely and causing the blade lock nut to back out and throw the blade.
I hope this answers your question.
Thanks again from the Husqvarna Technical Services Team.