Mark I CS
Had a 3.7 inch (94 mm) /L15 breech-loaded howitzer, derived from the World War I QF 3.7-inch mountain howitzer, instead of the 2-pounder gun. 40 rounds, mostly smoke, were carried. 
Tank, Cruiser, Mk IIA CS (A10 Mk IA CS)
Cruiser MkIIA CS
The CS (Close Support) version of the Mark II had a 3.7 in (94 mm) howitzer in the turret instead of the 2-pdr.[7] The standard ammunition load was 40 rounds smoke, and a few HE shells.
This weapon was derived from a World War I field howitzer, the QF 3.7-inch mountain howitzer.
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- Covenanter Mk I Close Support – Armed with 3-inch howitzer.[19]
(Covenanter tank - Wikipedia) - Covenanter Mk II CS – Armed with 3-inch howitzer.[19]
- Covenanter Mk III CS – Armed with 3-inch howitzer.[19]
- Covenanter Mk I Close Support – Armed with 3-inch howitzer.[19]
- Covenanter Mk IV – New production as the Mk II with the clutch changes of the Mk III.[19]
