UP FOR SALE!  13 QTY! API 2520 OP AMPS for all API gear including: 500 Series Modules, 550A 550b 560 2500 512c 3124+ etc... These are all tested MINT and guaranteed to arrive in perfect condition. These are very hard to get! Happy NEW YEAR! This great price is for one op-amp...this is a multiple item listing. Please let me know if you'd like all 15, I will ship for free!