The Inmarsat IsatPhone Pro 250 Unit Prepaid Airtime SIM Card offers 192 Voice to Landline Minutes with 180 days validity.</br></br>Product Description</br></br>This Prepaid Airtime SIM card is for the Inmarsat IsatPhone Pro and IsatPhone 2. Inmarsat IsatPhone Prepaid Unit Conversion Chart (Units per Minute) Divide the number of units purchased by the conversion rate below to calculate the number of minutes available for that particular service. PSTN Fixed (Land Line and US Cellular) - 1.3 Other Cellullar - 1.3 BGAN/FBB/SBB - 1.3 LandPhone/IsatPhone/FleetPhone - 1.3 SMS outgoing - 0.5 Inmarsat B - 3.4 Inmarsat M v/f/d - 2.9 Inmarsat Mini-M v/f/d - 2.5 Inmarsat GAN/Fleet/Swift - 2.5 Inmarsat Aero - 4.9 Iridium voice - 11 Globalstar voice - 8 Thuraya voice - 5 Other MSS carriers - 6.9 Minimum Call Duration 15 sec., Billing Increments 15 sec.</br><br/>http://www.amazon.com/gp/product/B01G5NWVH0