These are 37 pin connectors that work with RAINMASTER PROMAX UA and TRC COMMANDER and SIDEKICK. This is based on volume purchases. We do get back ordered on occasion since we are not trying to make a lot on one connector but rather a little on each and encouraging the purchase of larger volumes. I will keep you posted on what is back ordered and my advice is to get your orders in early and not two days before you need the connector. First come, first serve. All orders are shipped insured priority mail. Prices are based on total units regardless of the type. 1-19 connectors 12 station $21.00 24 station $26.00 32 station $36.00 20-99 connectors 12 station $16.00 24 station $20.00 32 station $30.00 100 or more connectors 12 station $13.90 24 station $17.50 32 station $27.00 SHIPPING AND HANDLING free on orders of 100 connectors or more. Texas residents need to add 8.25% sales tax.