Onga classic air venturi control - Chrome with 1" / 25mm socket. Used to control air bubbles from the jets in a spa bath. Has 8 dimples around scalloped top. Top, etc can be removed to replace older caps, etc. Serviceable part. These come in Chrome, White, and Gold.
Obsolete, so once stock is depleted, these will no longer be available.
- 50mm diameter cap
- 26mm diameter hole required