1/8" Male thread x 1/4" sae hose fitting with plastic cap.  These are sold as each

Fabco 1/8" Male thread x 1/4" Female thread.  Can be used generally on all 1" and smaller backflow line size. Ordering # 781074LL

Febco 1/4" MIP x 1/4" female thread test cock, low lead. Ordering # 781075LL

Typically used on 1 1/4", 1 1/2" and 2" assemblies.

Part # 18-860XL 1/8" x 1/4" lead free test cock.  This fits assemblies that are 1" or smaller in line size.

1/4" MIP X 1/4" SAE test adapter with plastic cap.   This is referred to as a "fast test cock" because the adapter is already built in.  This fits the 1 1/4", 1 1/2", and 2" sizes

This is only one test cock.  They do sell these in four packs, RK14-860XLFT

WILKINS TEST COCK, PACK OF 4.  1/8" MIP x 1/4" FIP.  LEAD FREE.

Closure sleeve test cock or #3 test cock for the Colt 200/300/400/500 as well as the Colt 200a/300a as well as the Maxim series.

WILKINS 1/4" MIP x 1/4" FIP LEAD FREE TEST COCK.  USED ON 1 1/4" - 2" SIZED ASSEMBLIES.

3/4" Female threaded, Closure sleeve test cock #3.  Also called closure sleeve test cock.  For Colt 200/300, Colt 200a/300a and Maxim series 6" - 10"

Watts 1 1/2" lead free full port ball valve with threaded ends and test cock. Ordering # 0792516.  Can be used for any model of Watts backflow.  Also is used as outlet ball valve for the 800M4 and LF800M4.

Watts LFFBV 1" Lead free ball valve, with test cock and T handle. Inlet ball valve also used as the outlet on the 800M4 and LF800M4 models.