It’s my first time selling, if I put “I Don’t Know Package Details” How will that effect the shippin

[itzmicah]

The only thing I know is the weight of the item and that is 9.6 ounces. 

[richard1rst]

Is this for the Nintendo Switch? Do you have it in your possession? MEASURE IT !

By the weigh, is that 9.6 ounce for the item? Shipping is based on the weight on the PACKAGE not the contents. You do realize that once you pack it for shipping it will weigh more.Shipping is based on size as well as weight. And in some cases the SIZE is more important than the weight. So, if you do not fill in ALL the information you are heading for problems. Do it right or don't do it at all.

[toysaver]

Put the item in a box.  Measure and weight the box with the item in it.  Put that weight and those measurements in the listing form.  

[janet9988]

It is your job as a seller to find out and supply the correct information on your listing.

Yes  it matters.

[electrola_man]

I never create a listing without knowing how I'm going to pack an item, how large the box is going to be, and how heavy the package will be.  I didn't think it was even possible to not have a shipping charge available for the buyer to see before buying.  If the buyer doesn't know what he/she is paying for shipping, likelihood of a sale would drop way off, I'd think.  It is really important to be sure of all of that detail, and enter it into the listing.  It's a good idea to also add a handling fee besides, because packaging materials aren't fee, and when Ebay charges a Final Value Fee on the sale, it includes the shipping charge.  As a hypothetical example, If the Final Value Fee percentage is 10% and you've charged the buyer $10 shipping, you only get $9.  You need to make sure that $9.00 covers postage and materials, unless you're willing to figure that some of the shipping cost is built into the item price.  

[tobaccocardyahoo]

I am not a new seller and I never list anything that I do not know everything I need to know about how I am going to pack it.

What kind of packaging material it requires to arrive safely, what size package, and which carrier I will use.

Deciding after you sell it runs the risks of not have what it takes to ship it safely, higher shipping cost than you charged, and all of the information necessary to ship it.

New sellers often underpack items, use too large a package for the shipping they charged, and find their product does not survive. Add to that they often ship a package which makes the customer think they are not professional.