New medium-based ("regular" socket") threaded porcelain socket with attaching metal cap and side screw (We have same socket without threads and we also have with metal screw-ring- see our store.)The threaded socket measures 1 9/16" wide (2" diameter includes thescrew ring) and is 2 1/8" tall including the bottom cap. The bottom threaded hole is 3/8" andworks with standard 1/8 IPS pipe. We sell for less in lots of 20, but you'd need to buy from that listing.We combine with other items to save shipping costs. We sell for less in lots of 10- see our store.$3.88 each.Shipping is $3.80 plus $.88 for each additional piece.Combined shipping- to get cheapest shipping costs (when buying different items)please buy what you need and “request invoice” so we can send invoice with lower shipping costs."How to Request Invoice when using shopping cart"---From your eCRATER cart, near the top of the page, move your mouse curser over our name “lamppartsguy” and a drop down menu will appear with the option to request invoice from seller.