They're wall fittings for attaching a shower hose to the in-wall water piping from the control valve. The white plastic insert is a check valve, to prevent dirty water from being siphoned back into the house's water supply piping. The long brass nipple has a standard 1/2" tapered pipe thread(IPS) and the short chrome thread is a standard 1/2" straight pipe thread for the hose to attach to. The fittings are made by a lot of manufacturers in different designs and shapes. Some have a built-in holder for the wand. The fittings are generic fit for standard piping and hoses. Link is for another generic fit fitting.

They're wall fittings for attaching a shower hose to the in-wall water piping from the control valve. The white plastic insert is a check valve, to prevent dirty water from being siphoned back into the house's water supply piping. The long brass nipple has a standard 1/2" tapered pipe thread(IPS) and the short chrome thread is a standard 1/2" straight pipe thread for the hose to attach to. The fittings are made by a lot of manufacturers in different designs and shapes. Some have a built-in holder for the wand. The fittings are generic fit for standard piping and hoses. Link is for another generic fit fitting.

References:

https://www.ebay.com/itm/Brass-Bathroom-Shower-Hose-Connector-Bath-Wall-Suppl...