28 mm x 15 mm straight coupler - reducing compression.
Brass compression fittings. BS 864-2:1983 or BS EN 1254:1988. They conform to both these standards apart from marking: a fitting conforms to the standards with which it is marked.
https://www.bes.co.uk/compression-reducing-coupling-28mm-x-15mm-17601/46251Compression Reducing Coupling - 28mm x 15mmhttps://www.bes.co.uk/media/catalog/product/2/8/28-mm-x-15-mm-straight-coupler-reducing-compression_min_17601_P_1.jpg3.53.5GBPInStock/Pipe Tube & Fittings/Pipe Fittings/Compression41671241424145<p>28 mm x 15 mm straight coupler - reducing compression.</p><p>Brass compression fittings. BS 864-2:1983 or BS EN 1254:1988. They conform to both these standards apart from marking: a fitting conforms to the standards with which it is marked.<br></p>BESt range00https://www.bes.co.uk/media/catalog/product/2/8/28-mm-x-15-mm-straight-coupler-reducing-compression_min_17601_L_1.jpg5056198110279add-to-cartfacet_type:Couplerspecial_price:3.500000cat_multi_facet_l1:Fittingsmore_sizes:17595,17596,17597,17598,17599,17600,17602products_related:20394,8748,18256,6921,9084,7621,16444,6962,21385,21031,7550sku:17601FittingsCoupler17595,17596,17597,17598,17599,17600,1760220394,8748,18256,6921,9084,7621,16444,6962,21385,21031,7550176013.500000No{"Type":"Straight Coupler"}ReducingBESt rangeBrassMetric28 x 15 mm