Silicone moulded heater hose shaped to suit the later heater unit as found in Kammtail/Series 2 Spiders, 1750/2000 GTVs & GT Juniors and Giulia and Berlina Saloons from about 1968 onwards. Specifications changed at different times on different models, so you need to check what your car is fitted with to make sure you order the right part. The earlier style hose is available under item WA017/S.
If you replace the heater hose, also check the gromment where the hose passes through the firewall. It is available under item RB073. Two required per RHD car. LHD cars use one of RB073 and one of RB056. Also straight lengths of heater hose are available under item WA048/S.