Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Estradiol acetate
Table title:
Available forms
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Route </th><th colspan=1 rowspan=1 > Ingredient </th><th colspan=1 rowspan=1 > Form </th><th colspan=1 rowspan=1 > Dose </th><th colspan=1 rowspan=1 > Major brand names </th></tr>
<tr> <td colspan=1 rowspan=3 > Oral </td><td colspan=1 rowspan=1 > Estradiol </td><td colspan=1 rowspan=1 > Tablets </td><td colspan=1 rowspan=1 > 0.1, 0.2, 0.5, 1, 2, or 4 mg per tablet </td><td colspan=1 rowspan=1 > Estrace, Ovocyclin </td></tr>
<tr> <td colspan=1 rowspan=1 > Estradiol acetateb </td><td colspan=1 rowspan=1 > Tablets </td><td colspan=1 rowspan=1 > 0.45, 0.9, or 1.8 mg per tablet </td><td colspan=1 rowspan=1 > Femtrace </td></tr>
<tr> <td colspan=1 rowspan=1 > Estradiol valerate </td><td colspan=1 rowspan=1 > Tablets </td><td colspan=1 rowspan=1 > 0.5, 1, 2, or 4 mg per tablet </td><td colspan=1 rowspan=1 > Progynova </td></tr>
<tr> <td colspan=1 rowspan=1 > Intranasal </td><td colspan=1 rowspan=1 > Estradiolb </td><td colspan=1 rowspan=1 > Nasal sprays </td><td colspan=1 rowspan=1 > 150 µg per spray (60 sprays per bottle) </td><td colspan=1 rowspan=1 > Aerodiol </td></tr>
<tr> <td colspan=1 rowspan=5 > Transdermal </td><td colspan=1 rowspan=5 > Estradiol </td><td colspan=1 rowspan=1 > Patches </td><td colspan=1 rowspan=1 > 14, 25, 37.5, 50, 60, 75, or 100 µg E2 per 24 hours for 3–4 or 7 days </td><td colspan=1 rowspan=1 > Climara, Estraderm, Vivelle </td></tr>
<tr> <td colspan=1 rowspan=1 > Gel dispensers </td><td colspan=1 rowspan=1 > 0.06% (0.87 or 1.25 g gel or 0.52 or 0.75 mg E2 per activation) </td><td colspan=1 rowspan=1 > Elestrin, EstroGel </td></tr>
<tr> <td colspan=1 rowspan=1 > Gel packets </td><td colspan=1 rowspan=1 > 0.1% (0.25, 0.5, or 1.0 g gel or 2.5, 5, or 10 mg E2 per packet) </td><td colspan=1 rowspan=1 > DiviGel, Sandrena </td></tr>
<tr> <td colspan=1 rowspan=1 > Emulsions </td><td colspan=1 rowspan=1 > 0.14% (1.74 g emulsion or 4.35 mg E2 per pouch; delivers 50 µg E2 per day) </td><td colspan=1 rowspan=1 > Estrasorb </td></tr>
<tr> <td colspan=1 rowspan=1 > Sprays </td><td colspan=1 rowspan=1 > 1.53 mg per spray </td><td colspan=1 rowspan=1 > Evamist </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=6 > Vaginal </td><td colspan=1 rowspan=5 > Estradiol </td><td colspan=1 rowspan=1 > Tablets </td><td colspan=1 rowspan=1 > 10 or 25 µg per tablet </td><td colspan=1 rowspan=1 > Vagifem </td></tr>
<tr> <td colspan=1 rowspan=1 > Creams </td><td colspan=1 rowspan=1 > 0.01% (0.1 mg E2 per 1.0 g cream) </td><td colspan=1 rowspan=1 > Estrace </td></tr>
<tr> <td colspan=1 rowspan=1 > Suppositoriesb </td><td colspan=1 rowspan=1 > 4 or 40 μg per suppository </td><td colspan=1 rowspan=1 > Ovocyclin </td></tr>
<tr> <td colspan=1 rowspan=1 > Inserts </td><td colspan=1 rowspan=1 > 4 or 10 µg per insert (replaced daily for 2 weeks and then twice weekly) </td><td colspan=1 rowspan=1 > Imvexxy </td></tr>
<tr> <td colspan=1 rowspan=1 > Rings </td><td colspan=1 rowspan=1 > 2 mg per ring (provides 7.5 µg E2 per 24 hours for 3 months) </td><td colspan=1 rowspan=1 > Estring </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Estradiol acetate </td><td class="highlighted"  colspan=1 rowspan=1 > Rings </td><td class="highlighted"  colspan=1 rowspan=1 > 12.4 or 24.8 mg per ring (provide 50 or 100 µg E2 per 24 hours for 3 months) </td><td class="highlighted"  colspan=1 rowspan=1 > Femring </td></tr>
<tr> <td colspan=1 rowspan=8 > Intramuscular injection </td><td colspan=1 rowspan=1 > Estradiola </td><td colspan=1 rowspan=1 > Ampoules </td><td colspan=1 rowspan=1 > 1.0 mg/mL </td><td colspan=1 rowspan=1 > Juvenum E </td></tr>
<tr> <td colspan=1 rowspan=1 > Estradiol benzoate </td><td colspan=1 rowspan=1 > Vials/ampoules </td><td colspan=1 rowspan=1 > 0.167, 0.2, 0.333, 1, 1.67, 2, 5, 10, 20, or 25 mg/mL </td><td colspan=1 rowspan=1 > Progynon-B </td></tr>
<tr> <td colspan=1 rowspan=1 > Estradiol cypionate </td><td colspan=1 rowspan=1 > Vials/ampoules </td><td colspan=1 rowspan=1 > 1, 3, or 5 mg/mL </td><td colspan=1 rowspan=1 > Depo-Estradiol </td></tr>
<tr> <td colspan=1 rowspan=1 > Estradiol dipropionateb </td><td colspan=1 rowspan=1 > Vials/ampoules </td><td colspan=1 rowspan=1 > 0.1, 0.2, 0.5, 1, 2.5, or 5 mg/mL </td><td colspan=1 rowspan=1 > Di-Ovocylin, Progynon-DP </td></tr>
<tr> <td colspan=1 rowspan=1 > Estradiol enantate </td><td colspan=1 rowspan=1 > Vials/ampoules </td><td colspan=1 rowspan=1 > 5 or 10 mg/mL (available only in combination with a progestin) </td><td colspan=1 rowspan=1 > Perlutal, Topasel </td></tr>
<tr> <td colspan=1 rowspan=1 > Estradiol undecylateb </td><td colspan=1 rowspan=1 > Vials/ampoules </td><td colspan=1 rowspan=1 > 100 mg/mL </td><td colspan=1 rowspan=1 > Delestrec, Progynon Depot 100 </td></tr>
<tr> <td colspan=1 rowspan=1 > Estradiol valerate </td><td colspan=1 rowspan=1 > Vials/ampoules </td><td colspan=1 rowspan=1 > 5, 10, 20, or 40 mg/mL </td><td colspan=1 rowspan=1 > Delestrogen, Progynon Depot </td></tr>
<tr> <td colspan=1 rowspan=1 > Polyestradiol phosphate </td><td colspan=1 rowspan=1 > Vials/ampoules </td><td colspan=1 rowspan=1 > 40 or 80 mg per vial/ampoule </td><td colspan=1 rowspan=1 > Estradurin </td></tr>
<tr> <td colspan=1 rowspan=1 > Subcutaneous </td><td colspan=1 rowspan=1 > Estradiolc </td><td colspan=1 rowspan=1 > Implants </td><td colspan=1 rowspan=1 > 20, 25, 50, or 100 mg per implant (usually replaced every 6 months) </td><td colspan=1 rowspan=1 > Estradiol Implants, Meno-Implant </td></tr>
<tr> <td colspan=5 rowspan=1 > Abbreviations: E2 = Estradiol. Footnotes: a = Encapsulated in microspheres. </td></tr>
</table>
Question:
What are the possible doses of estradiol acetate for vaginal rings, and what are the sizes of the rings?
Answer:
Estradiol acetate comes in the form of 12.4 or 24.8 mg vaginal rings that release 50 or 100 μg/day estradiol for 3 months (Femring).