Talley lightweights. Combo ring and base.

From their info -

for Alloy lightweight scope mounts -

Low Mounts for 1 inch scope tube with scopes up to a 40mm objective.... for 30mm scope tube - for scopes up to a 44mm objective lens with a sporter-weight barrel

Medium Mounts 30mm scope tube - for scopes up to a 50mm objective lens if your rifle has a sporter-weight barrel.

High Mounts 1 inch scope tube for scopes up to a 50mm objective lens if your rifle has a sporter-weight barrel. 30mm scope tube for scopes up to a 56mm objective lens if your rifle has a sporter-weight barrel

Extra-High Mounts 1 inch scope tube for scopes up to a 56mm objective lens if your rifle has a sporter-weight barrel. 30mm scope tube for scopes up to a 56mm objective lens if your rifle has a has a heavier contoured barrel