Here are 3 Miner's Carbide Cap Lamp Bottoms/Bases, 2 AUTOLITE and 1 GUY'S DROPPER (made by SHANKLIN MFG. CO.). Each has 2 rows of ribbing, but the SHANKLIN/GUY'S DROPPER center ribbing is lower. SHANKLIN base is "Pre-1920" and is stamped with the oval LOGO on the bottom. AUTOLITE bases are early-1920's and have no stamping. All bases have signs of use and age - base on left has crack at bottom edge. Winning bidder is to pay $4.50 postage including Delivery... Confirmation. Good luck bidding! NOTE: I am happy to combine shipping on my items won in the same week. Please send me a message BEFORE PAYING, so I know you are bidding on another item. I will send an invoice later, hopefully saving you some postage. Thanks!