Receiver drier for many of the later TVRs. This is a high quality receiver drier with a built in sight glass. It is recommended that the drier is changed if the air conditioning system needs recharging or develops a leak. The receiver drier removes moisture from the air conditioning system and is effectively one of the few service items in the air conditioning system. Not replacing the drier if the system is opened to atmosphere is a false economy and not recommended. Note the TVR Sagaris uses a different drier, TVR P0653. This drier TVR P0121 uses 2 TVR P0059 o rings to seal to pipework.