Features:

1、The I.D.of upper and lower sub is equal to that of casing,but smaller than that of closing sleeve,eliminating the possible damage to the closing sleeve during tripping or drilling out accessories.

2、All accessories are non-rotating and made of easily drillable materials.

3、A Pump-Down Opening Plug instead of a Free-Fall Opening Plug can be used for a continuous two-stage cementing operation.