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-elbow-28mm-17688/39694Compression Equal Elbow - 28mmhttps://www.bes.co.uk/media/catalog/product/2/8/28-mm-x-28-mm-equal-compression-elbow-imported_min_17688_P_1.jpg5.075.07GBPInStock/Pipe Tube & Fittings/Pipe Fittings/Compression/Lower Prices/Pipe Tube & Fittings4167424212414241454241<p>28 mm x 28 mm equal compression elbow.</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-28-mm-equal-compression-elbow-_min_17688_L_1.jpg5056198111047add-to-cartfacet_type:Elbowspecial_price:5.070000campaign_category:Pipe Fittingscampaign_was:4.13cat_multi_facet_l1:Fittingsis_on_sales:Nomore_sizes:17683,17684,17686,17687products_related:7623,9570,8199,16444,23208,7308,7389,7550,21112,19494,23366sku:17688Pipe Fittings4.13FittingsElbowNo17683,17684,17686,176877623,9570,8199,16444,23208,7308,7389,7550,21112,19494,23366176885.070000No{"Connection":"Compression","Demountable\/Reusable":"No","Equal\/Reducing":"Equal","Finish":"Brass","Fitting Type":"Elbow","Material":"Brass","Size":"28 mm","Type":"Elbow"}Equal90°BESt rangeBrassMetric28 mm