These are the between pieces: the fittings that sit where line meets coupling or port. Reducing unions step between BSP sizes, the three eighths to quarter and half to quarter parallel forms here, bayonet fittings in quarter inch male and female serve the twist lock lines, and quick release brackets mount the connection points to the wall.
The Speedfit assortments are the workshop insurance: push fit coupling kits in 32 piece 6 and 8mm, 20 piece 10mm and 15 piece 12mm forms, with the 30 piece metric and imperial thread adaptor assortment covering the odd port that nothing in the drawer fits. One kit stocks the sizes a ring main install or repair keeps reaching for.
The pick follows the same two end method as every fitting: read the thread or tube size each side must be, and the listing names both. Brake and air line seals sit here for the sealing faces, and the couplings, adaptors and hoses leaves around this one carry the patterns, steps and lines themselves.
Anything worn past reading goes over WhatsApp on 07754288583 as a photo of both ends, and comes back named.