Check the listing for details. BRASS-PLATED KEYLESS LAMP SOCKETS TR-13. Condition: New. Listed at 2.90 USD. Brass-plated medium-based keyless socket-single circuit (you need a separate switch to turn off and on). Bottom cap has 3/8" threaded hole that works with 1/8 IPS pipe. No set screw. We combine with other items to save shipping costs. $2.90 each. Shipping is $3.88 plus $.18 for each additional piece. KEYLESS SOCKETSLESS THAN 10 BRASS-PLATED $2.90 EA eBay # 120640238813 NICKEL-PLATED $2.90 EA ebay # 204267114610 ANT BR-PLATED $2.90 EA ebay # 383535323314 LOT OF 10 BRASS-PLATED $20 EA ebay # 204267134649 NICKEL-PLATED $20 EA ebay # 381000941397 ANT BR-PLATED $20 EA ebay # 383535323312 LOT OF 20 BRASS-PLATED $36.80 EA ebay # 200623643903 NICKEL-PLATED $36.80 EA ebay # 385465064797 ANT BR-PLATED $36.80 EA ebay # 383535323311 Combined shipping- to get cheapest shipping costs (when buying different items)please buy what you need (WITHOUT SHOPPING CART) and “request invoice” (BEFORE YOU PAY) so we can send invoice with lower shipping costs. SHOPPING CART DOES NOT SEEM TO WORK FOR COMBINED SHIPPING.